Pat, a real estate broker, gave Mary a signed written offer to purchase Mary's home.The offer provided that it must be accepted by 12:00 noon on December 1, 1998.At 1:00 p.m. on December 1, 1998, Mary delivered a signed acceptance to Pat.Under these circumstances,

A. Mary has accepted the offer because she accepted within a reasonable time.

B. Pat made an irrevocable firm offer because she is a merchant.

C. Pat has estopped from revoking due to Mary's reliance on the offer.

D. Mary's acceptance is too late, and there is no contract.