Step 1: Understanding the question.
The question asks about the reason RK and SG are not speaking to each other. We need to determine which statement provides the necessary information.
Step 2: Analyzing the statements.
(I) RK and SG do not know each other: This statement does not address the issue of why they are not speaking, only that they don't know each other. It doesn’t explain any conflict.
(II) RK and SG were friends earlier but have recently fought with each other: This statement provides a clear reason for why they are not speaking — they have had a fight.
Step 3: Conclusion.
The correct answer is (B) If only statement II is required to answer the question, as it provides the necessary context about their relationship and the reason they are not speaking.