Upon graduation from high school, a young man wanted to enroll in a nine-month program at a community college to study to be an electrician, but he could not afford tuition and the costs of being unemployed for that time period. His uncle told him that if he enrolled and participated in the program, he would pay his tuition and living expenses for the time involved, and that he would also pay him a $1,000 bonus for each "A" he earned as a final grade in a class. The young man told his uncle that he would enroll in the program. The next day, the young man's grandfather called and told him that he had learned of the uncle's offer and that if the uncle failed to pay the young man as promised, he (the grandfather) would. The young man attended the program and earned "As" as final grades in three classes. Shortly thereafter, the uncle died, and the executor of the uncle's estate refused to pay the young man the bonus for each of the three "As."

The young man will not be successful in trying to enforce his grandfather's promise because:

A. The contract was illusory
B. The contract was oral.
C. There was no consideration flowing to the grandfather.
D. The fact that the young man received nine months' worth of free education and living expenses was sufficient compensation for his efforts in earning the three "As."