$($a$)(4\%)$ Explain the differences between superclass$/$subclass and category in EER model regarding the

subclass$$s inheritance of attributes$/$relationships from its superclasses.

$($b$)(3\%)$ Describe the drawbacks for the mapping of superclass$/$subclass with overlapping constraints to

relations by using the approach of multiple relations for subclass relations only.

$($c$)(3\%)$ Explain how to derive the primary key of the relation mapping from a weak entity type.