He made us work.

The correct answer is: A. We were made to work by him.

The other options are incorrect because they do not accurately reflect the meaning of the sentence.

• Option B, “We would work by him,” suggests that the speaker and others would choose to work for him. However, the sentence does not indicate that the speaker and others had a choice in the matter.
• Option C, “We might work by him,” suggests that there is a possibility that the speaker and others would work for him. However, the sentence does not indicate that there is any doubt about whether or not the speaker and others will work for him.
• Option D, “We have to work by him,” suggests that the speaker and others are obligated to work for him. However, the sentence does not indicate that the speaker and others are under any obligation to work for him.

In conclusion, the correct answer is: A. We were made to work by him.