Answer:
Cynthia should inform Juan of the defects and seek for a replacement or refund, while returning the defective shirts to Juan.
Explanation:
Since Cynthia cannot sell the shirts to her own customers because of the defective stitching, it implies that the goods were not in the right condition when she accepted delivery. She should be able to negotiate for a return and refund or replacement of the affected shirts. Cynthia should also ensure that future goods received are properly and thoroughly inspected before accepting delivery to forestall the arguments that could arise from the present situation.