In this English grammar question, a sentence is given in active voice. Select the option that best expresses the same idea in passive voice. Sentence: "Two engines are pulling the train up the hill."

Introduction / Context:

The given sentence describes an action that is happening at the present moment. It states that two engines are pulling the train up the hill. The question asks you to select the passive voice sentence that keeps this present continuous action and makes the train the subject.

Given Data / Assumptions:

- Original sentence: "Two engines are pulling the train up the hill."

- Subject in the active sentence: "two engines".

- Object: "the train".

- The tense is present continuous: "are pulling".

- The phrase "up the hill" shows direction and must remain in the passive sentence.

Concept / Approach:

For present continuous passive, we use the pattern "is being" or "are being" plus the past participle of the main verb. Since the new subject "the train" is singular, we use "is being pulled". The directional phrase "up the hill" stays after the verb phrase, and the original subject "two engines" is introduced in a "by" phrase.

Step-by-Step Solution:
Step 1: Identify subject, verb, and object. Subject: two engines. Verb phrase: are pulling. Object: the train. Direction: up the hill. Step 2: Move "the train" into the subject position in the passive sentence. Step 3: Use "is being pulled" to form the present continuous passive. Step 4: Keep the phrase "up the hill" after the verb phrase. Step 5: Add "by two engines" as the agent phrase and check that the meaning remains unchanged.

Verification / Alternative check:

The sentence "The train is being pulled up the hill by two engines." correctly uses present continuous passive, includes the direction phrase, and shows that two engines are performing the action. The meaning remains the same as in the active sentence, but the focus is now on the train.

Why Other Options Are Wrong:

Some alternatives change the tense to present simple, present perfect, future, or past continuous, all of which shift the time or nature of the action. Other options remain in active voice and therefore fail to satisfy the requirement. A few are grammatically awkward, with unusual word order or missing auxiliary verbs. Because of these problems, they do not serve as accurate passive transformations.

Common Pitfalls:

One frequent issue is choosing the wrong auxiliary verb for the new subject and writing "are being pulled" when the subject is singular. Another is forgetting to include the word "being" in continuous passive forms. Students may also misplace directional phrases so that the sentence becomes confusing. To avoid these mistakes, follow the structure "subject plus is being plus past participle plus direction plus by phrase".

Final Answer:

The correct passive voice sentence is "The train is being pulled up the hill by two engines."