You are the business analyst for your organization and you are completing the verify requirements...

 Functional is not a characteristic of a requirement, but a type of requirement. A functional requirement describes what the system or solution should do, such as the features, functions, behaviors, or capabilities1. A characteristic of a requirement is a quality or attribute that makes the requirement good or effective. There are different sources that list different characteristics of a requirement, but some of the common ones are: clear, complete, consistent, correct, feasible, modifiable, unambiguous, and testable2345. These characteristics help to ensure that the requirement is well-defined, understood, verified, and validated. References:

Functional vs Non-functional Requirements: What’s the Difference?

1.4 Characteristics of a Good Requirement - InformIT

How To Write a Good Requirement? 14 Qualities | Insights Spotter

Needs and Solutions, Requirements and Designs - IIBA®

Effectively! – Requirement Characteristics - ArgonDigital