Let us consider phone_number ,which can take single or several values . Treating phone_numberas an _________ permits instructors to have several phone numbers (including zero) associated with them.
(a) Entity
(b) Attribute
(c) Relation
(d) Value
The question was posed to me in a national level competition.
This interesting question is from Entity-Relationship Design Issues topic in division Database Systems Design and Implementation of Database Management