A can be A-> derivable if and only if __________

a-can-be-a-derivable-if-and-only-if-a-a

A can be A-> derivable if and only if __________
A. A-> A is actually a production
B. A->B, B-> A exists
C. Both A. and B.
D. None of the mentioned
Right option is A. A-> A is actually a production

The format says: If A->B is a production, B is called A-derivable.Thus A to be A-derivable, a production : A-> A need to exist.