Select the most appropriate meaning of the given idiom.
Knuckle down
Show answer & explanation
Correct answer: B
Explanation
The correct answer is option 2 i.e. To start working or studying hard.
Idiom: Knuckle down
Meaning: To begin to work hard, especially after a period of not working or procrastinating.
Example: After the holidays, she decided to knuckle down and prepare seriously for her exams.
Hence, the chosen option will be correct.