Solution

The idiom "toot your own horn" means boasting about your achievements or abilities. In this case, the speaker is acknowledging that they did well on a test but doesn't want to appear to be boasting. The other options are unrelated idioms. a) Pull someone's leg - Playfully tease or joke with someone, often by telling them something that is not true to see if they believe it. b) Kick the bucket - Euphemism for dying or passing away. c) Let the cat out of the bag - Accidentally reveal a piece of secret or confidential information. d) Toot my own horn - Brag or boast about one's accomplishments or abilities. e) Hit the nail on the head - Accurately identify or describe the root cause of a problem or issue. Find the errorneous part in the given sentence.