Select the most appropriate meaning of the given idiom.

To make castles in the air

to create impossible dreams or hopes

The most appropriate meaning of the idiom "to make castles in the air" is >to create impossible dreams or hopes.<

This idiom is used to describe someone who is daydreaming or fantasizing about things that are unlikely or impossible to achieve. It is a metaphor for building castles in the sky, which is a futile and unrealistic endeavor.

For example, you might say that someone is making castles in the air if they are talking about becoming a famous actor without any training or experience.

The other options are not correct.

• To be very ambitious: This means to have a strong desire to achieve great things.
• To accomplish difficult tasks: This means to achieve something that is challenging or difficult.
• To show signs of cowardice: This means to be afraid or hesitant to do something.