Fill in the blank with the verb in its correct form: I _______ very tired. So I lay down on the bed and went to sleep. (be) A. am B. will be C. was D. have been

The correct answer is C. was.

The sentence is in the simple past tense, so the verb must be in the past tense as well. The other options are not in the past tense.

• A. am is in the present tense.
• B. will be is in the future tense.
• D. have been is in the present perfect tense.

The sentence is about a past event, so the verb must be in the past tense.