3. Here is a list of functional dependencies ABC D CDEF DE A DE B CFB BDF E AE C BC F ABE AB F A minimal cover for this set is an equivalent set of FD's obtained from the original set by doing the following two steps in order: 1. Eliminate attributes from the left sides of FD's, if possible. That is, if XY A is in the set, but A is in the closure of Y, then replace this FD by, YA. 2. Eliminate entire FDS, when possible. That is, if X A is in the set, but A is in the closure of X computed without using the FD X A then eliminate X A. Note that the order in which steps (1) and (2) are applied to the various FD's and attributes may influence the final minimal cover. Find all minimal covers for this set of FD's. Then, identify from the list below one dependency that must, must not, or may be in a minimal cover. a) AB D is in all minimal covers. O b) DE B is in all minimal covers O c) AB E is in no minimal cover. O d) ABC D is in all minimal covers