The Nyingma sect of Buddhism became the dominant religious tradition in Sikkim during the medieval period due to:

The correct answer is: a) Royal patronage.

The Nyingma sect of Buddhism became the dominant religious tradition in Sikkim during the medieval period due to royal patronage. The first king of Sikkim, Phuntsog Namgyal, was a devout Nyingma Buddhist and he established the Nyingma order as the state religion. He built many Nyingma monasteries and temples, and he supported Nyingma monks and scholars. This royal patronage helped to spread the Nyingma tradition throughout Sikkim.

The other options are not correct.

• b) Popular support. While the Nyingma sect did have popular support in Sikkim, it was not the only Buddhist sect that was popular. The Kagyu and Gelug sects were also popular, and they each had their own followings.
• c) Missionary activities. There were some Nyingma missionaries in Sikkim, but they did not have a significant impact on the spread of the Nyingma tradition. The Nyingma tradition spread primarily through royal patronage.
• d) Geographic proximity to Tibet. Sikkim is located in the Himalayas, which is close to Tibet. However, this geographic proximity did not have a significant impact on the spread of the Nyingma tradition in Sikkim. The Nyingma tradition spread primarily through royal patronage.