Final answer:
Abstinence is the most effective protection against STD infections, while condoms provide a high level of protection.
Step-by-step explanation:
The best protection against an STD infection is abstinence. Abstinence means choosing not to engage in sexual activity, which eliminates the risk of contracting an STD. Condoms also provide a high level of protection when used correctly and consistently, but they are not 100% effective. Washing the body thoroughly does not provide any protection against STDs. Going to the doctor for a monthly checkup is important for overall health, but it does not prevent STD infections.
Learn more about Protection against STD infections