Final answer:
Option (c) Load testing, stress testing, component testing, portability testing includes only non-functional testing types that check aspects of software not related to specific functions, such as performance under stress and adaptability to different environments.
Step-by-step explanation:
The correct answer to the question: Which of the following list contains only non-functional tests? is option (c) Load testing, stress testing, component testing, portability testing. Non-functional testing refers to aspects of the software that may not be related to a specific function or user action, such as scalability, performance, and security. It's crucial to distinguish non-functional tests from functional tests, which focus on verifying the functionality of the software.
Load testing and stress testing both assess the performance of the software under varying loads to ensure it can handle expected and unexpected user traffic. Component testing, also known as module testing or unit testing, is typically categorized as a functional testing method, but in the context of this list, it could be meant to refer to the testing of individual components for non-functional attributes like scalability or maintenance. Finally, portability testing checks if software can be transferred from one environment to another, which is also a non-functional aspect of software quality.