Question

change the sentence into passive voice
he was really very sorry for what he had alone.​

Answer 1

Answer:

This problem cannot be solved by anyone.

Explanation:

A sentence is in active voice when the subject performs the action.

A sentence is in passive voice when the subject receives the action.

While converting a sentence from active to passive, the subject becomes the object and vice versa. When the active voice is in simple present form, passive voice takes the simple past form.

Subject + verb + object (active voice)

Therefore as per the rule option C is correct.

Option A and D are not in simple past form therefore incorrect. Whereas option B changes the meaning of the sentence, as the sentence is a generalized statement and does not refer to any specific set of subject. Therefore options A, B, D are incorrect.