You want Multi-factor authentication for your system.AFunctional requirementBNon-functional requirementSUBMIT

Multi-factor authentication for a system is a Non-functional requirement.

Here's why:

Functional requirements are the basic system interactions, the system's behavior, or functionalities. They describe what the system should do or provide to users.

Non-functional requirements, on the other hand, are the criteria that judge the operation of a system, rather than specific behaviors. They are the requirements that specify criteria that can be used to judge the operation of a system, rather than specific behaviors. This includes performance requirements, security requirements, software quality attributes, etc.

In this case, Multi-factor authentication is a security requirement. It doesn't describe a specific behavior or interaction of the system, but rather a characteristic or feature that enhances the system's security. Therefore, it is a non-functional requirement.