Which method enhances account security by requiring more than one verification method?

Two-factor authentication enhances account security by requiring users to provide two different forms of verification before they can gain access to their accounts. This method combines something the user knows, such as a password, with something the user possesses, like a mobile device that receives a verification code. The use of two distinct factors significantly reduces the likelihood of unauthorized access because even if one factor (like the password) is compromised, the attacker would still need the second factor to proceed.

In contrast, single sign-on consolidates multiple applications into one authentication process, thus not necessarily enhancing security but improving usability. Password reset processes focus on the recovery of account access but do not inherently add layers of protection. Biometric scanning, while a strong security feature, is often a singular authentication method rather than a combination of multiple methods. Therefore, two-factor authentication is the correct answer, as it specifically incorporates multiple verification methods to strengthen security.