Bill Has a Right Against Heather and Assigns It for $100

Multiple Choice

Bill has a right against Heather and assigns it for $100 to Dan.Later,Bill grants Heather a release.Bill:

A) is liable to Dan for damages because he breached an implied warranty.
B) has no liability to Dan because he did not expressly warrant that he would not impair the assignment.
C) has no liability to Dan because the only implied warranty he made was that the assigned right actually existed at the time of the assignment.
D) was acting contrary to public policy by assigning a contractual right for money.