The correct answer is C. BSNL.
BSNL is the major telecom service provider of Ladakh. It has a wide network of towers and provides good coverage in most parts of the region. It also offers a variety of plans and services to suit the needs of its customers.
Gio is a new telecom service provider that has recently launched its services in Ladakh. It is yet to establish a strong network and offers limited coverage in some parts of the region.
Vi is a leading telecom service provider in India. It has a good network in most parts of the country, but its coverage in Ladakh is limited.
Aircel is a telecom service provider that has been facing financial difficulties in recent years. It has shut down its operations in many parts of the country, including Ladakh.
In conclusion, BSNL is the major telecom service provider of Ladakh. It has a wide network of towers and provides good coverage in most parts of the region. It also offers a variety of plans and services to suit the needs of its customers.