For each relational schema given below and its corresponding functional dependencies (FDs): R(A, B, C, D): AB rightarrow C, C rightarrow D and D rightarrow A R(A, B, C, D): AB rightarrow C, BC rightarrow D and CD rightarrow A and AD rightarrow B R(A, B, C, D, E): AB rightarrow C, C rightarrow D, D rightarrow B and D rightarrow E answer the following questions (for each of the above three cases separately): find all candidate keys of the relation. Given the keys you defined in the previous step, find the functional dependencies (only from the ones listed above) that violate BCNF. Decompose the relations to satisfy BCNF. Specify which FD is used to make the decomposition. If there is multi-step decomposition, then indicate each step along with which FD used for the decomposition