Which of the following is an example of a functional requirement?

The choice that identifies a functional requirement is a clear definition of a specific functionality that the system must provide. In this case, stating that "the system must allow the user to amend customer details" describes a particular behavior or action that the system should have in response to user interactions. This requirement focuses on what the system should do, which is the core of functional requirements.

Functional requirements detail the capabilities that a system must offer to its users, including tasks, functions, or processes. They directly relate to the specific actions that the product needs to perform, which enhances the user experience and supports the business goals.

In contrast, other options illustrate non-functional requirements, such as system performance, usability, and compliance. For example, the requirement that "the system must load within 2 seconds" refers to performance specifications rather than direct functionalities. Likewise, the accessibility requirement focuses on the environment in which the system operates, and the privacy compliance requirement addresses regulatory standards rather than specific user interactions or capabilities. Understanding these differences helps distinguish between what a system should accomplish (functional) and how it should behave or meet certain standards (non-functional).