Select the most appropriate meaning of the given idiom.

Under the nose of 

Almost in the presence of 

The correct answer is Almost in the presence of. The idiom "under the nose of" means right in front of someone's face, but without their knowledge or awareness. It is often used to describe something that is happening that someone should be aware of, but is not. For example, you might say "The thief stole the jewels right under the nose of the security guard."

The other options are incorrect. "A difficult work" is not an idiom. "To take leave" means to say goodbye. "To survey" means to look at something carefully.