Under which of the following circumstances is maintenance testing required?

A circumstance where maintenance testing is required is A. Migration of software onto a new platform. Migration of software onto a new platform is a type of change that affects the delivered software product and requires maintenance testing to ensure that the software product still works correctly and consistently on the new platform. A new platform can be a different hardware, operating system, network, database, browser, etc., that supports or interacts with the software product. Migration of software onto a new platform can introduce compatibility issues, performance issues, security issues, etc., that need to be detected and resolved by maintenance testing. A detailed explanation of migration testing can be found in [A Study Guide to the ISTQB® Foundation Level 2018 Syllabus], page 82.