A new application for planning journeys on public transport is being developed that will work...

Analysis:

Compatibility testing is essential for applications that are designed to work across various hardware and software environments, particularly for mobile devices which can have diverse specifications and operating systems.

C. To evaluate the degree to which it can effectively and efficiently be adapted for different or evolving hardware environments:

This option addresses the core purpose of compatibility testing for a mobile application. It ensures that the application works as intended across different mobile devices and operating systems, which is crucial for public transport applications that must function reliably on various devices used by the public.

Explanation of Incorrect Options:

A. To evaluate the degree to which it is operational and accessible when required for use:

This is more related to availability and reliability rather than compatibility.

B. To evaluate the degree to which its functions facilitate the accomplishment of specified tasks and objectives:

This pertains to functionality testing, not compatibility.

D. To evaluate the degree to which the system is operational and accessible when required for use:

This duplicates option A and is not directly related to compatibility.

References:

The ISTQB CTAL-TTA syllabus covers compatibility testing and its relevance in ensuring applications function correctly across different environments and hardware configurations.

Sources:

ISTQB-CTAL-TTA Syllabus

General knowledge on compatibility testing practices.