Final answer:
None of the provided options correctly represent single factor authentication. Single factor authentication requires only one method to verify a user's identity, such as a password, PIN, or biometric scan used by itself, not in combination with other methods.
Step-by-step explanation:
The question asks us to identify which option represents single factor authentication. Single factor authentication means using one method to verify a user's identity. Option A) A security person to verify you is not a specific form of technological authentication. Option B) A key card and password, and Option C) A password and PIN text involves two methods and are thus examples of two-factor authentication. Option D) An eye scan and fingerprint involves biometric methods, which are also two factors when used together. Therefore, none of these examples represent single factor authentication. In practice, single factor authentication would be something like just a password, just a PIN, or just an eye scan but not in combination with any other method.