Jan Promises Eli $4,000 for One of His Original Paintings

Jan promises Eli $4,000 for one of his original paintings on the condition that she receives $1 million from her mother's will.In this case:

A) Jan has made an illusory promise.
B) Jan's promise is legally sufficient unless Jan knows she cannot inherit the $1 million.
C) Jan has made a conditional promise which is not sufficient to form consideration.
D) Jan's promise is legally inadequate and the courts will therefore not enforce it.