Rafi Offers a Tour of Bay Harbor Aboard His Sailboat

Rafi offers a tour of Bay Harbor aboard his sailboat, Sea Siren, to Tiara's Travel Group for $500. Referring to the prices for similar tours, Tiara's says, "We'll pay no more than $400." Rafi's offer is

A) ​still open.
B) ​terminated.
C) ​rejected and subject to a counteroffer.
D) ​revoked.