The correct answer is - C. Buddhism.
The Buddhism, unlike the other suggested religions, is not a religion that is only practiced by one ethnic group, but it is practiced by multiple ethnic groups, in multiple different countries.
Even though the Buddhism has originated in India, it doesn't really have a following base there, but it can be found in Southeast Asia, China, Korea, Japan, Mongolia, and even Sri Lanka Nepal, and Bhutan, as well as parts of Russia, like in the Tuva Republic, and in the plains north of the Caucasus Mountain Range.
