Which of the Following Is True of an Assignment of a Right

Which of the following is true of an assignment of a right?

A) The unconditional assignment of a contract right retains all the assignor's rights.
B) The obligor is entitled to performance from the assignor.
C) The assignor loses the right to sue the obligor directly for nonperformance in an unconditional assignment.
D) The obligor cannot raise personal defenses against the assignee.