Select the most appropriate meaning of the underlined idiom in the given sentence.

Trying to find my lost ring in the college is like looking for a needle in a haystack.

Doing something impossible

The most appropriate meaning of the underlined idiom in the given sentence is doing something impossible.

The idiom "looking for a needle in a haystack" means to try to find something that is very difficult or impossible to find. It is often used to describe a situation where someone is searching for something that is very small or insignificant in a large or overwhelming place.

In the given sentence, the woman is trying to find her lost ring in the college. This is a very large place, and the ring is very small. Therefore, it is very difficult or impossible for her to find it.

The other options are not correct.

• Making a big deal of a small thing: This does not mean to do something impossible.
• Doing something secretly: This does not mean to do something impossible.
• Doing something unimportant: This does not mean to do something impossible.