Final answer:
A correctly drawn context diagram usually contains one central bubble representing the system, with the exact number of surrounding bubbles varying based on the system's interactions with external entities.
Step-by-step explanation:
A context diagram is a high-level, graphical representation of a system that depicts the system (often shown as a single process) and its interaction with external entities. In terms of bubbles included in a correctly drawn context diagram, there is typically one single bubble in the center representing the system or process, surrounded by multiple bubbles or boxes that represent the external entities (or actors) that interact with the system. Therefore, a correctly drawn context diagram should have one central bubble for the system itself. No specific number of external entities is required; it depends on the complexity and scope of the system being analyzed.