Option A — Both (A) and (R) are correct and (R) is the correct explanation of (A).
The 1956 Act made Sinhala the only official language, alienating Tamils, which eventually led to civil war.
Source: Majoritarianism in Sri Lanka, Chapter 1
The Reason directly explains the Assertion: the majoritarian Act of 1956 was a key step that increased Tamil alienation, leading to conflict and ultimately civil war. So (R) correctly explains (A), making Option A the right choice. Remember — if both statements are true AND the reason logically causes/explains the assertion, choose A.