Lexington and Kaci enter into a contract that requires Kaci to pay Lexington $$500$ for a dishwasher. Lexington delivers the dishwasher on a Tuesday. Kaci begins using the dishwasher on Wednesday. A month later,

Kaci is still using the dishwasher but has not yet paid for the dishwasher. What may Lexington assume?

Lexington may assume that Kaci has accepted the dishwasher.

Lexington may assume Kaci has not accepted the dishwasher because, to accept goods, the buyer must serve on the seller a formal letter of acceptance, and Kaci has not done this yet.