Assertion (A): The following intramolecular aldol reaction occurs.
Reason (R ): The carbanion does not add to C-4 because a strained four-membered ring would result.
A. Both (A) and (R ) true and (R ) is the correct explanation of (A).
B. Both (A) and (R ) are true but (R ) is not correct explanation of (A).
C. (A) is true but (R ) is false.
D. (A) is false but (R ) is true.