Locking an account after a certain number of password attempts, using a CAPTCHA test, and requiring strong passwords can prevent what security issue?

• A. Two-factor authentication
• B. Rate limiting
• C. Account lockout after several failed attempts, CAPTCHA, and strong passwords
• D. IP blocking

Answer: (C)

These controls are aimed at stopping brute-force login attempts. Locking the account after a few failed tries limits how many guesses an attacker can make before access is blocked. A CAPTCHA helps distinguish real users from automated bots that try many passwords. Requiring strong passwords reduces the odds that a guessed password is correct in the first place. Put together, these measures make it much harder for someone to gain unauthorized access through credential guessing or credential stuffing.

Other options describe related ideas but don’t fit this exact combination as the outcome being prevented. Two-factor authentication adds a separate verification step, rate limiting is a broader technique that can help but isn’t described by this specific set, and IP blocking is another control that’s not what this trio directly demonstrates.