Which of the following is an example of something you have in terms of authentication?

The correct answer is a smart card or phone app, as these represent something you have in the context of authentication mechanisms. In authentication, "something you have" refers to a physical token or device that provides access, verifying the identity of the user. Smart cards and mobile apps can store digital certificates or cryptographic keys, making them secure methods for confirming a user's identity in combination with something the user knows, like a password.

A fingerprint scan represents something you are, which is a biometric authentication method, while a written password and a secret question both fall under the category of "something you know." Each of these options serves different purposes in authentication systems, but only smart cards and phone apps qualify as "something you have."