Parker Owes Money to Both Gregory and Williams

Multiple Choice

Parker owes money to both Gregory and Williams.He agrees with Williams to assign to him the whole of his property if Williams will pay the debt due to Gregory.The property is duly assigned,but Williams fails to pay Gregory.Gregory and Parker sue in equity to compel performance of William's promise.In this situation,

A) the lawsuit by Parker and Gregory will succeed.
B) Gregory acquired an equitable right through the mediation of Parker's agreement.
C) Parker will be regarded as trustee for Gregory.
D) Parker need not have joined Gregory in the law suit.
E) all of the above