Final answer:
The backward pass in the Critical Path Method is used to determine the latest start and finish times for activities, which is crucial for calculating slack times and ensuring that the project completion date is not jeopardized. The correct option is c.
Step-by-step explanation:
The purpose of the backward pass in the Critical Path Method (CPM) technique is to determine the latest time each activity can start and finish. This is essential for calculating the slack or float time, which is the amount of time that a task can be delayed without causing a delay to subsequent tasks or the overall project completion date.
The backward pass involves working backward from the project's end date. For instance, if a project is set to conclude on December 31 and the last critical task takes 10 days, the latest that task can begin is December 21 without jeopardizing the project's end date.
Using the heuristic of working backwards, as in the example provided where planning a trip from Washington, D.C. to Philadelphia is required, the backward pass would involve determining the latest possible departure time to ensure on-time arrival. The correct option is c.