Sid received from Ruby a check that had been made out payable to Ruby's order and properly endorsed by her. In which of the following situations did Sid give value and become a dollar in due course of the check?

a. Sid received the check in exchange for promising to give Ruby's daughter piano lessons.

b. Sid received the check as a graduation gift from Ruby.

c. Sid received the check as partial payment of a loan he had made to Ruby.

d. Ruby have the check to Sids daughter for her gift to Sid.