Which of the following is usually the test basis for integration testing?

Integration testing primarily focuses on assessing the interactions between integrated components or systems. The test basis for integration testing is typically found in the technical specification, as it provides detailed descriptions of how different modules or components interact with each other. This specification outlines the architecture, interfaces, and protocols used, which are critical for designing integration test cases that effectively validate the data flow and interactions between the different parts of the system.

While functional specifications describe the functionality from the user's perspective, and requirement specifications outline what the system should achieve, it is the technical specification that offers the necessary details on how components will work together. This ensures that integration testing can systematically address the connections, data exchange, and overall functioning of the system as a collection of cohesive parts. Thus, the primary focus during integration testing aligns closely with the insights derived from the technical specifications.