Step 1: Recall shipyards.
Mazagon Dock Shipbuilders Limited (Mumbai) is India’s leading warship-building yard.
Step 2: Contribution.
It builds destroyers, submarines, and frigates for the Indian Navy.
Step 3: Eliminate options.
(B) Kolkata: Garden Reach Shipbuilders also builds vessels but Mazagaon is primary.
(C) Chennai: No major warship yard.
(D) None: Incorrect, because Mazagaon exists.
Step 4: Conclusion.
Correct answer: (A) Mazagaon.