In the following question, a sentence is given in Active voice. Out of the four alternatives, select the one which best expresses the same idea in Passive voice: He shall have bought a car.

Introduction / Context:
This question tests your understanding of voice change in English grammar, specifically the transformation of a sentence from Active voice to Passive voice. The tense used here is the future perfect tense. To get the passive form correct, you must preserve both the tense and the meaning of the original sentence while shifting focus from the doer of the action to the object of the action.

Given Data / Assumptions:

• Active sentence: He shall have bought a car.
• Subject in Active voice: He.
• Object in Active voice: a car.
• Helping verbs: shall have (future perfect auxiliary).
• Main verb: bought (past participle of buy).

Concept / Approach:
In voice change, the object of the Active sentence becomes the subject of the Passive sentence. The basic structure of future perfect Active is will or shall + have + past participle. The corresponding Passive structure is will or shall + have been + past participle. We keep the tense markers the same and insert been to create the passive form. The agent of the action is then introduced with by, such as by him or by her.

Step-by-Step Solution:
Identify the tense: “shall have bought” shows the future perfect tense.Write the passive auxiliary structure for future perfect: will or shall + have been + past participle.Move the object “a car” to the subject position in the Passive sentence.Use the correct auxiliary: “A car will have been” plus the past participle “bought”.Place the original subject at the end with by: “by him”.Thus, the Passive sentence is: “A car will have been bought by him.”

Verification / Alternative check:
Check meaning: “He shall have bought a car” and “A car will have been bought by him” both indicate that at some future point, the action of buying will already be completed. The time sense and completion are preserved. The only difference is that the focus shifts from he (the doer) to a car (the receiver of the action), which is exactly what a proper change of voice should do.

Why Other Options Are Wrong:
Option A, “A car was being bought by him,” is past continuous Passive, not future perfect. Option B, “A car was bought by him,” is simple past Passive. Option D, “A car would have been bought by him,” uses would have instead of shall or will have and expresses a conditional or hypothetical situation, which changes the meaning. Only option C keeps the future perfect sense intact.

Common Pitfalls:
Students often forget the word been in perfect Passive forms and write structures like will have bought by him, which are incorrect. Always remember that perfect Passive requires have been or had been or will have been. Also, keep the tense helper (will or shall) consistent with the original sentence and do not replace it with would unless the meaning changes to a conditional form.

Final Answer:
The correct Passive voice form is A car will have been bought by him.