Hi I am stuck on this problem

AB+AB=CDC Given a crypt-arithmetic prob Variables and their domains: Constraints: B+B=10x1+CA+A=10C+D+x1 Which of the following assign a. A=2,B=5,C=0,D=5 b. A=1,B=6,C=2,D=3 c. A=1,B=5,C=0,D=3 d. A=4,B=5,C=0,D=9