To answer this question, let's go through each option to understand why it is correct or incorrect:
Option A) Requirements - Incidents can be raised against requirements if there are issues or errors in the specified requirements. Therefore, this option is incorrect.
Option B) Documentation - Incidents can be raised against documentation if there are mistakes or inconsistencies in the provided documentation. Therefore, this option is incorrect.
Option C) Test Cases - Incidents can be raised against test cases if there are defects or failures identified during the testing process. Therefore, this option is incorrect.
Option D) Improvements suggested by users - Incidents are typically not raised against improvements suggested by users. These suggestions are usually considered as enhancements rather than issues or defects. Therefore, this option is correct.
The correct answer is D) Improvements suggested by users. This option is correct because incidents would not be raised against improvements suggested by users.