The correct answer is 'Improve your work or behaviour.' Key Points - The meaning of the underlined idiom/phrase 'Pull your socks up' is to make an effort to improve your work or behaviour because it is not good enough. - 'Pullyour socks up' - Example: He's going to have to pull his socks up if he wants to stay in the team. - Therefore, the correct answer is 'Improve your work or behaviour.'