Tom Enters a Coffee Shop at Which He Has an Open

Multiple Choice

Tom enters a coffee shop at which he has an open account,fills a cup of cof?fee,holds it up so the cashier can see it,acknowledges the cashier's nod,and walks out with the coffee,knowing that he will be billed for it at the end of the month.Tom has formed

A) an express contract.
B) an implied-in-fact contract.
C) an implied-in-law contract.
D) a quasi contract.