To answer this question, let's go through each option to understand why it is correct or incorrect:
Option A) Use case diagrams are the primary tool to document requirements - This option is TRUE. Use case diagrams are a visual representation of the functional requirements of a system. They show the interactions between actors (users or external systems) and the system itself. Use case diagrams are commonly used to document and communicate the requirements of a system.
Option B) Use cases provide the basis of communication between sponsors and developers in the planning phase - This option is NOT mentioned in the question. Therefore, we cannot determine its truthfulness based on the given information.
Option C) Use cases description provides a good source to identify domain concepts - This option is NOT mentioned in the question. Therefore, we cannot determine its truthfulness based on the given information.
Option D) A fully-dressed use case should include both "whats" and "hows" so that they are ready for "realization" - This option is NOT TRUE. A fully-dressed use case includes the "what" or the goal or objective of the use case, but it does not include the "how" or the implementation details. The "how" or the implementation details are typically documented separately, such as in the form of activity diagrams or sequence diagrams.
The correct answer is A) Use case diagrams are the primary tool to document requirements. This option is correct because use case diagrams are commonly used to document and communicate the requirements of a system.