Find a set of FDs that is consistent with a closed attribute set A set of attributes X is called cosed (with respect to a given set of funcsonal dependencies) irXX. Consider a relation with schema RIA, B, C, D) and an unknown set of functional dependencies. For each closed attribute set below, give a set of functional dependencies that is consistent with t. a, All sets of attributes are closed b. The only closed sets are andA, B, C, D C. The only closed sets are{},{4,n},and{A,B,C,D)