On December 1, Euphonia, a famous singer, contracted with Boito to sing at Boito's theater on December 31 for a fee of $25,000 to be paid immediately after the performance.
a. Euphonia, for value received, assigns this fee to Carter.
b. Euphonia, for value received, assigns this contract to sing to Dumont, an equally famous singer.
c. Boito sells his theater to Edmund and assigns his contract with Euphonia to Edmund. State the effect of each of these assignments.