Which type of dome is most commonly used in islamic architecture?
a. corbel dome
c. tholos
b. onion dome
d. rotunda

Correct answer choice is :

B) Onion dome

Explanation:

An onion dome is a roof whose appearance matches an onion. Such roofs are usually bigger in width than the drum upon which all sit, and their height normally beats their diameter. These bulbous buildings decrease easily to a point.