The correct option is D Mahayanism
Kanishka was the most powerful ruler of the Kushan Empire. His conquests and patronage of Buddhism played an important role in the development of the Silk Road, and the transmission of Mahayana Buddhism from Gandhara across the Karakoram range to China. He was a patron of Buddhism and he called the 4th Buddhist council in the Kundalvana of Kashmir in 78 AD. His greatest contribution to Buddhist architecture was the Kanishka stupa at Peshawar, Pakistan.