Question

Fill in the blank with a suitable option:
All the lights in Terry's room are turned off. He ____________ sleeping.

• A. Must have been
• B. Had to be
• C. Must be
• D. Must not be

Answer 1

The correct option is C Must be

The correct answer is Option C.

MUST BE expresses certainty of a fact.

In the given sentence, the speaker is saying that it is certain that Tom is sleeping because the lights are turned off.

Thus MUST BE is the correct answer.

The remaining options are incorrect because:

MUST HAVE BEEN is present perfect, while the sentence is in the present tense.

HAD TO BE is the past tense.

MUST NOT BE is used when something is not the case, it would have been correct if Tom was not sleeping.