Which of the following is an example of two-factor authentication?

Two-factor authentication enhances security by requiring two distinct forms of identification before granting access to an account. This method typically involves something the user knows, like a password, combined with something the user possesses, such as a one-time code sent to their mobile device.

When a user enters a password, that serves as the first layer of security. The subsequent requirement to enter a one-time code adds a second layer, ensuring that even if someone guesses or steals the password, they would still need the additional code sent to the user’s device to gain access. This dual-layer approach significantly reduces the likelihood of unauthorized access compared to methods that rely solely on a password or other single factors.

In contrast, using just a password, answering security questions, or sending a password to an email does not meet the criteria for two-factor authentication. These methods generally rely only on a single piece of information, which may not provide the same level of security as combining two different types of authentication factors.