The question asks for generic product risk factors that should be considered by a Technical Test Analyst. Here are the detailed reasons for each of the options:

a) A high number of performance efficiency defects in the software: This is indeed a significant product risk. Performance efficiency defects can severely affect the user experience and the overall performance of the system, making it a crucial factor for technical test analysts to consider.

b) Inaccurate arithmetic calculations in key business areas: While this is critical, it is more of a functional risk specific to the business domain rather than a generic product risk. It concerns the accuracy of the system's operations rather than its overall quality attributes.

c) Particularly complex code: Complex code is a generic product risk factor because it can lead to increased chances of defects, difficulties in maintenance, and challenges in achieving good test coverage. Complex code often requires more rigorous testing to ensure reliability.

d) Communication issues with geographically distributed teams: This is a project risk rather than a product risk. While it can affect the testing process and coordination, it does not directly relate to the inherent risks in the product itself.

e) Usability issues with the design of the user interface: Usability issues are indeed significant but are more specific to the user experience aspect rather than being a broad product risk factor.

From the analysis, the generic product risk factors that stand out are "a high number of performance efficiency defects" and "particularly complex code," making the correct answer B. a and c.

This answer is validated by referring to the ISTQB CTAL-TTA syllabus and sample exam answers, which emphasize the importance of performance efficiency defects and code complexity as key product risk factors​​​​​​.