Consider a relation R(A,B,C,D,E,F) with the following set of functional dependencies: ACDEFBD (a) Based on these functional dependencies, there is one minimal key for R. What is it? (b) Add to the above set of functional dependencies the dependency AB. Now suppose we want A to be a key. Name one more functional dependency that, if added to the set, makes A a key. As an additional restriction, the new functional dependency must have only one attribute on the left-hand side and only one attribute on the right-hand side