The correct option is A Buddhists
The Sinhalese people speak Sinhala, an Indo-Aryan language, and are predominantly Theravada Buddhists, although a small percentage of Sinhalese follow branches of Christianity. The Pali chronicles (e.g., the Mahavamsa) claim that the Sinhalese as an ethnic group are destined to preserve and protect Buddhism. In 1988 almost 93% of the Sinhala speaking population in Sri Lanka were Buddhist. Hence, Option A is correct. The rest of the religious observers are minorities in Sri Lanka, hence, incorrect.