The software not being able to meet the desired response time is an example of a failure. A failure is an event in which a component or system does not perform a required function within specified limits. A failure is observable by end users or testers as a deviation from expected results. defines a failure as follows:

Failure: Deviation of the component or system from its expected delivery, service or result.

B, C, and D are incorrect answers. The software not being able to meet the desired response time is not an example of a defect (B), an error ©, or not a defect (D). A defect is a flaw in a component or system that can cause it to fail to perform its required function. An error is a human action that produces an incorrect result. Not a defect is a term used to describe an incident report that is rejected or closed as invalid or out of scope. defines these terms as follows:

Defect: A flaw in a component or system that can cause the component or system to fail to perform its required function.

Error: A human action that produces an incorrect result.

Not a defect: An incident report status indicating that there is no defect in relation to this incident report.