Si Promises to Pay His Personal Assistant Tery $50,000 in Consideration

Multiple Choice

Si promises to pay his personal assistant Tery $50,000 in consideration of the services she provided over the years. Si never makes the payment. Si's promise is

A) enforceable for the entire $50,000.
B) enforceable to the extent of what Tery's services were actually worth.
C) not enforceable because the consideration is in the past.
D) not enforceable because the failure to pay is an unforeseen difficulty.