The Kattupakkam Shipyard near Chennai is known for shipbuilding and:

Submarine repairs
Boat manufacturing
Oil rig construction
Luxury yacht building

The correct answer is: a) Submarine repairs.

The Kattupakkam Shipyard near Chennai is a major shipbuilding and submarine repair facility in India. It is owned and operated by the Mazagon Dock Limited (MDL), a state-owned company. The shipyard was established in 1948 and has since built a wide range of ships, including submarines, destroyers, frigates, and corvettes. It is also capable of carrying out repairs and refits of submarines.

The shipyard is located on the east coast of India, about 20 kilometers from Chennai. It has a total area of about 1,000 acres and a waterfront of about 2 kilometers. The shipyard has a dry dock with a capacity of 10,000 tons and a floating dock with a capacity of 20,000 tons. It also has a number of workshops and other facilities for the construction and repair of ships.

The Kattupakkam Shipyard is a major employer in the region. It employs about 10,000 people, including skilled workers, engineers, and managers. The shipyard is also a major contributor to the Indian economy. It generates about $1 billion in revenue annually and exports about $200 million worth of ships each year.

The Kattupakkam Shipyard is a state-of-the-art facility that is capable of building and repairing a wide range of ships. It is a major employer in the region and a major contributor to the Indian economy.

The other options are incorrect because they are not the primary activities of the Kattupakkam Shipyard.

Option b) Boat manufacturing is not the primary activity of the Kattupakkam Shipyard. The shipyard is primarily known for shipbuilding and submarine repairs.

Option c) Oil rig construction is not the primary activity of the Kattupakkam Shipyard. The shipyard does not have the capability to construct oil rigs.

Option d) Luxury yacht building is not the primary activity of the Kattupakkam Shipyard. The shipyard does not have the capability to build luxury yachts.