He completed the story on time.

The correct answer is: B. The story was completed by him on time.

The other options are incorrect because they do not accurately describe the action of the sentence.

• Option A is incorrect because it uses the past perfect tense, which is used to describe an action that was completed before another action in the past. In this sentence, there is no other action in the past that the completion of the story is being compared to.
• Option C is incorrect because it uses the progressive tense, which is used to describe an action that is ongoing or in progress. In this sentence, the action of completing the story is not ongoing or in progress; it is completed.
• Option D is incorrect because it uses the simple present tense, which is used to describe an action that is habitual or that occurs regularly. In this sentence, the action of completing the story is not habitual or regular; it is a one-time event.

The sentence “He completed the story on time” is in the simple past tense. The simple past tense is used to describe an action that was completed at a specific time in the past. In this sentence, the action of completing the story is completed at a specific time in the past, which is when the story was due.