Final answer:
The correct answer is C. must have. In this sentence, the phrase 'it must have rained last night' is used to indicate a deduction or an assumption based on evidence. The verb phrase 'must have' is used to express a strong probability or certainty about a past event.
Step-by-step explanation:
The correct answer is C. must have.
In this sentence, the phrase 'it must have rained last night' is used to indicate a deduction or an assumption based on evidence. The verb phrase 'must have' is used to express a strong probability or certainty about a past event.
In contrast, the options 'might have ', 'must have been', 'would have', and 'no correction required' are grammatically incorrect or do not convey the intended meaning.
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