Please explain

1. (30pts.) Consider a relation R(A, B, C, D, E) with functional dependencies Compute the following closure and determine which one is the candidate key candidate key? Yes, No candidate key? Yes, No candidate key? Yes, No candidate key? Yes, No candidate key? Yes, No candidate key? Yes, No candidate key? Yes, No candidate key? Yes, No candidate key? Yes, No candidate key? Yes, No AB+ AC+= BC+ CD+ DE+=