Select the correct passive form of the given sentence - Who asked you…

The correct answer is Option (4) → By whom were you asked to drive my car?

Passive of a question beginning with "who":

Change	Active	Passive	Why
Agent (by ...)	Who	By whom	“Who” is the doer, so in the passive it becomes the agent “By whom” (the object form), placed at the start.
Tense kept	asked	were ... asked	Be + past participle in the same tense, with question order: simple past “asked” becomes were ... asked, with “were” before the subject.
Full sentence	Who asked you to drive my car?	By whom were you asked to drive my car?

"You" stays "you".

The sentence is still a question, so it ends with a question mark.

Example: Who wrote this letter? → By whom was this letter written?

Why the Other Options are Incorrect?

Option 1: By who you are asked to drive my car ? — Incorrect.

• After the preposition "by", the object form whom is needed, not "who".
• "are asked" changes the past tense to the present.
• The subject comes before the verb, so it is not question order.

Option 2: By whom you were asked to drive my car ? — Incorrect. The tense is right, but the word order is that of a statement: a question needs "were you", not "you were".

Option 3: By whom you were asked to drive my car. — Incorrect. It has statement order and ends with a full stop, so it is no longer a question.