The correct answer is option 1: "To stop yourself from saying something because it would be better not to."

This phrase is an idiomatic expression used when someone refrains from speaking or expressing their thoughts, especially when it might be considered inappropriate, offensive, or harmful. "Bite your tongue" suggests self-restraint and the act of physically biting down on one`s tongue to prevent uttering something.

Option 2, "To bite off your tongue while eating," is a literal interpretation of the phrase and does not reflect the intended meaning.

Option 3, "To feel sorry," does not capture the essence of the idiom, which primarily focuses on controlling one`s words rather than expressing remorse or regret.

Option 4, "To ask someone something that you want," is unrelated to the phrase "bite your tongue" and does not align with its commonly understood meaning.

Therefore, option 1 is the most appropriate expression that matches the idiom`s meaning.