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                                                                   EXHIBIT 99.6


                             STOCK OPTION AGREEMENT

         THIS AGREEMENT, made the 6th day of June, 1996, between C3, Inc., a
North Carolina corporation (the "Company"), and Douglas G. Waltz, (the
"Optionee").

                                R E C I T A L S:

         In consideration of One Dollar ($1.00) and other good and valuable
consideration paid to the Company by the Optionee, the receipt of which is
acknowledged by the Company, the Company and the Optionee hereby agree as
follows:

         1. The Company hereby grants to the Optionee the right and option to
purchase all or any part of an aggregate of Ten Thousand (10,000) shares of the
common stock of the Company (the "Shares") at the purchase price of Four Dollars
($4.00) per share (the "Option"). The parties acknowledge that the fair market
value of the Shares on the date of this agreement is equal to Four Dollars per
share.

         2. The period during which the Option may be exercised (the "Option
Period") is five (5) years from the date hereof.

         3. The Optionee may exercise the Option by giving written notice to the
Company at the Company's principal office. That notice shall specify the number
of Shares to be purchased and the purchase price to be paid therefor, and shall
be accompanied by the payment of the purchase price in cash or by certified
check. The notice shall be deemed to have been given either when delivered
personally or when mailed, postage prepaid, to the Secretary of the Company at
the principal office of the Company. The Company shall issue a certificate or
certificates for the Shares purchased pursuant to the exercise of the Option as
soon thereafter as practicable.

         4. The Option shall not be transferable by the Optionee and may be
exercised only by the Optionee during his lifetime.

         5. This Agreement shall be binding upon and shall inure to the benefit
of the parties hereto and their respective executors, administrators,
next-of-kin, successors or assigns.

         6. Any controversy of claim arising out of or relating to the Agreement
shall be settled by arbitration in Charlotte, North Carolina, in accordance with
the rules of the American Arbitration Association.

         7. The Option is granted on the condition that all Shares purchased
hereunder shall be acquired for investment purposes only and not for the purpose
of resale or distribution. If deemed necessary or appropriate in the opinion of
legal counsel for the Company, certificates issued evidencing Shares acquired
pursuant to the exercise of the Option shall bear a restrictive legend setting
forth the provisions of this Section 7 in substantially the following form:

                  "The shares represented by this certificate have not been
         registered with the Securities and Exchange Commission or with any
         state agency and may not be transferred in the absence of an effective
         registration with respect thereto or an opinion of counsel satisfactory
         to the Company that such registration is not required."

         8. If there is any change in the Shares subject to the Option through
merger, consolidation or reorganization, or if the Company declares a stock
split or a stock dividend to holders of Shares that is distributable on stock of
the same class, or if there is an issuance to such holders of rights to
subscribe to stock of the same class, or if there is a change in the capital
structure of the Company, the Company shall make such adjustments with respect
to the Option or any provisions of this Agreement as it deems equitable to
prevent dilution or enlargement of the rights of the Optionee.

         9. The Agreement may be modified or amended by written agreement of the
parties hereto.



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         10. Except as otherwise provided herein, this Agreement shall be
construed and enforced according to the laws of the State of North Carolina.

         IN WITNESS WHEREOF, this Agreement has been executed in behalf of the
Company and by the Optionee on the day and year first above written.


                                          C3, INC.


                                          By: 
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                                                       President


Attest:

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       Secretary


[Corporate Seal]

                                          OPTIONEE

                                                                          (SEAL)
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