The correct answer is Knowledge based factor.

A password is a secret that the user knows so it is a Knowledge based factor. Knowledge based factor refers to authentication based on something the user can recall such as a password or a PIN and it is distinct from items or biometric traits.

Possession factor is incorrect because it refers to something the user has such as a hardware token or a smartphone. A password is not a physical object that the user carries.

Behavioral factor is incorrect because it depends on patterns like typing rhythm or gesture habits. A password is a static secret and not a behavioral pattern.

Location based factor is incorrect because it uses geolocation or network origin to influence authentication. A password does not depend on where the user is located.

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