Select the most appropriate meaning of the given idiom.

He's sitting on the fence

He can't take a decision

The most appropriate meaning of the given idiom is (4) He can't take a decision.

The idiom "sitting on the fence" means to be undecided or to avoid taking a side in a conflict or debate. The person is literally sitting on the fence, which is a neutral position. This idiom is often used to describe someone who is afraid to make a decision or who is trying to please everyone.

The other options do not fit the meaning of the idiom.

• He can't stop trying means that he is constantly trying to do something.
• He can't do anything seriously means that he is not serious about anything he does.
• He can't hide himself means that he is not able to keep his thoughts or feelings hidden.