Question

I racked my brains to solve this difficult problem.

• A. I read a large number of books.
• B. I consulted several people.
• C. I used my commonsense.
• D. I subjected my mind to hard thinking.

Hint:

Rack one's brains means to think very hard, not to read or ask others.

Answer 1

The Correct Option is D

This question tests whether you know the everyday meaning of the idiom rack one's brains. Look at what each option claims and see which one truly restates that meaning.

1. I read a large number of books: this talks about reading, but racking your brains never means going through books, so this option misses the sense.
2. I consulted several people: this shows the person got outside help, while the idiom is about working the problem out alone in your own mind.
3. I used my commonsense: commonsense is quick, everyday judgment, but the idiom points to a harder, more strained effort than that.
4. I subjected my mind to hard thinking: this is exactly what racking your brains means, forcing your mind to work hard on a tough problem.

So option D is correct, since it directly describes the strained, hard thinking the idiom refers to.

Let's summarize:

• Rack one's brains means to think very hard or strain your mind over a problem.
• It does not involve reading, asking others, or casual judgment.

Once you know this idiom, matching it to the right paraphrase becomes simple.