Correct Answer & Explanation
Option B
• This sentence expresses a universal truth or a scientific fact. In such cases, the tense of the reported speech does not change, even if the reporting verb is in the past tense. So, 'revolves' remains 'revolves'.
• The reporting verb 'said' remains 'said' as there is no object after it. So, option C is incorrect.
• The connector 'that' is used for assertive sentences. So, option D is incorrect as it uses 'asked if'.