Select the most appropriate meaning of the given idiom.

Up in arms

to be angry

The most appropriate meaning of the idiom "up in arms" is >to be angry.<

It means to be very angry and upset, and to be ready to fight or protest. The idiom is often used to describe someone who is reacting strongly to something they disagree with.

The other options are not correct.

• To be nervous: This does not mean to be angry.
• To be defensive: This does not mean to be angry.
• To be rude: This does not mean to be angry.