Correct Answer: Option C - Zarowar Tank
Zarowar Tank is the correct answer as it represents a collaborative project between L&T and DRDO in the field of armoured warfare.
Arjun Tank Mk1A: While this is an indigenous main battle tank developed by DRDO, the primary industrial partner for Arjun Tank is Heavy Vehicles Factory (HVF) at Avadi, not L&T.
Sarvatra Bridge System: This is a mobile bridging system developed by DRDO, but L&T is not the primary industrial partner for this system.
Zarowar Tank: This is the collaborative armoured warfare project between L&T and DRDO.
Nag Missile Carrier: The Nag missile is an anti-tank missile developed by DRDO, but its carrier vehicle (NAMICA) is not primarily an L&T-DRDO collaboration.