The correct answer is option 4, INS Viraat, which is a decommissioned aircraft carrier.

Option 1, INS Talwar, is not a decommissioned aircraft carrier. INS Talwar is a class of guided missile frigates in the Indian Navy.

Option 2, INS Chakra, is also not a decommissioned aircraft carrier. INS Chakra is a nuclear-powered attack submarine that was leased from Russia.

Option 3, INS Khanderi, is a Scorpène-class submarine that was commissioned in the Indian Navy in 2019. It is not an aircraft carrier.

INS Viraat, on the other hand, was a Centaur-class aircraft carrier that served in the Indian Navy. However, it was decommissioned in 2017 after more than three decades of service. It was the flagship of the Indian Navy before being retired from active duty.