Which of the following king summoned the fourth Buddhist Council?

Kanishka

The correct answer is Option 4- Kanishka

The fourth Buddhist Council was held under the patronage of Kanishka in Kashmir in 72 AD.

Buddhist Councils: Location and Presiding Figures

First Council:
Location: Sattapanni Caves, Rajgriha (present-day Rajgir)
Patronage: King Ajatashatru
Presided by: Mahakassapa (monk)

Second Council:
Location: Vaishali
Patronage: Uncertain
Presided by: Uncertain (possibly several elders)

Third Council:
Location: Pataliputra (present-day Patna)
Patronage: Emperor Ashoka
Presided by: Moggaliputta Tissa (monk)

Fourth Council:
Location: Kundalvana, Kashmir
Patronage: King Kanishka
Presided by: Vasumitra and Ashvaghosha (monks)