What do two or more concurrent tasks depend on?

The correct answer highlights the relationship between tasks in a project management or systems analysis context. When discussing concurrent tasks, the term "predecessor task" refers to a task that must be completed before another task can begin. In the scenario where multiple tasks are running simultaneously, they might depend on one or more predecessor tasks to provide the necessary inputs, resources, or conditions for them to operate effectively.

Understanding the dependency on predecessor tasks is crucial for successful project planning and execution. It helps in determining the sequence of activities, ensuring that necessary prerequisites are met before proceeding with dependent tasks. By recognizing these dependencies, system analysts can better forecast project timelines, allocate resources efficiently, and mitigate risks associated with overlapping task execution.

Other options in the question represent different concepts that do not specifically address the dependencies between concurrent tasks. Joint tasks consider collaborative efforts rather than sequential dependencies. Successor tasks refer to what follows after a task is completed, and resource allocation involves managing resources but doesn't inherently depict the timing relationship necessary for understanding task dependencies. Therefore, focusing on predecessor tasks provides a clearer framework for addressing questions about dependencies among concurrent activities.