DIRECTIONS: A sentence with an underlined idiomatic expression is given. What is the meaning of this idiomatic expression 'A feather in one's cap' in the sentence given below?
If this clinical trial is successful, it will be a real feather in her cap.
1
an obstacle that hinders the progress
2
None of the above
3
a dress or accessory that helps you look beautiful
4
an achievement that you can be proud of