Zeta Is Contracted to Perform a Violin Solo for Pat

Zeta is contracted to perform a violin solo for Pat. Zeta assigns the contract to Roy. Which of the following statements is true about delegation of duty in this case?

A) This is a valid delegation of Zeta's duty as Zeta has entered into a novation with Roy.
B) This is a valid delegation of Zeta's duty because Zeta does not want to play for Pat.
C) This is not a valid delegation of Zeta's duty to play because all delegations must be expressly stated in the assignment contract.
D) This is not a valid delegation of Zeta's duty to play because the contract is one in which Zeta's personal skill as a musician is an essential part of the agreement.