Which of the following is a permanent birth control method?

Tubal ligation is considered a permanent birth control method because it involves a surgical procedure where a woman's fallopian tubes are cut, tied, or blocked. This prevents sperm from reaching the egg, thereby eliminating the possibility of pregnancy. Unlike other methods listed, which are temporary and can be discontinued or reversed, tubal ligation is designed to be irreversible for most women.

In contrast, condom use and diaphragm use are barrier methods that can be used during sexual activity but do not provide a long-term solution, as they need to be applied each time. Birth control pills require daily administration and can be stopped at any time, leading to a potential return to fertility. Therefore, tubal ligation stands out as a definitive and lasting option for those seeking irreversible contraception.