The correct answer is: C. Deleg Namgyal.
The first mosque in Leh was built in 1533 during the reign of Deleg Namgyal, the second king of Ladakh. The mosque, known as the Jama Masjid, is located in the heart of Leh and is one of the oldest mosques in the Ladakh region. It is a simple, rectangular building with a white exterior and a green dome. The mosque has a capacity of about 500 people and is used for both daily prayers and Friday prayers.
Shah Mir was a Kashmiri ruler who founded the Shah Mir dynasty in Kashmir in the 14th century. He was not the king of Ladakh.
Gulab Singh was a Dogra ruler who conquered Ladakh in 1846. He was not the king of Ladakh during the time the first mosque was built.
Rgyalbu Rin-Chen was a Buddhist monk who lived in the 14th century. He was not the king of Ladakh.