For Several Months, Yolanda Has Been Picking Up Tom's Suit

Multiple Choice

For several months, Yolanda has been picking up Tom's suit at the cleaners on the first Monday of each month. Each month, Tom pays her $25 when she delivers the suit to his office. This month she picks up the suit and delivers it to Tom's office. Tom refuses to pay Yolanda the $25, stating that they did not have a contract. What type of contract did Tom and Yolanda have?

A) An implied contract
B) An express contract
C) A quasi contract
D) A bilateral contract
E) A unilateral contract