Choice "C" is correct. The Sales Article imposes a duty of good faith on all parties.
Choice "d" is incorrect. Certain provisions of the Sales Article differentiate between merchants and nonmerchants (e.g., only a merchant makes the implied warranty of merchantability).
Choice "a" is incorrect. The Sales Article applies to all sales of goods. The $500 limit refers to the Statute of Frauds within the Sales Article.
Choice "b" is incorrect. Most provisions of the Sales Article can be varied by agreement (e.g., warranties may be disclaimed).
