The correct answer is: B. Mohan says, “Teacher is not at home.”
The other options are incorrect because they do not accurately reflect what Mohan said. Option A, “Mohan said, ‘Teacher is not at home,'” is incorrect because it uses quotation marks, which indicate that Mohan’s words are being directly quoted. However, Mohan’s words are not being directly quoted in this sentence. Option C, “Mohan says, ‘Teacher was not at home,'” is incorrect because it uses the past tense, which indicates that Mohan is talking about something that happened in the past. However, Mohan is not talking about something that happened in the past; he is talking about something that is happening right now. Option D, “Mohan said, ‘Teacher was not at home,'” is incorrect for the same reason as Option C.
In conclusion, the correct answer is: B. Mohan says, “Teacher is not at home.”