Detailed Explanation:

The correct answer is A. The project will be delayed.

The critical path is the sequence of activities that determines the shortest possible completion time for the project. Activities on the critical path have no slack or float available. Therefore, if the duration of one of those activities increases, the overall project completion time will most likely also increase.

Why A is correct:

A delay in a critical-path activity directly affects the final project completion date because there is no available schedule flexibility in that path.

From a Quality Management Excellence perspective, project control requires understanding which activities directly influence delivery timing. Critical-path analysis helps focus attention on the areas where schedule variation matters most.

Why the other options are not correct:

B. Additional resources will have to be made available.

This may be considered as a recovery action, but it is not the most likely automatic result.

C. Costs will increase.

Costs may increase, but not necessarily. The most direct and likely consequence is schedule delay.

D. All activities in the project will be affected.

Only activities dependent on the critical-path sequence or the overall completion date are directly affected, not necessarily every activity.

Quality Management Excellence interpretation:

Effective project management depends on identifying schedule-sensitive activities and controlling them carefully. Best practice is to monitor critical-path tasks closely because any increase in their duration directly threatens project completion timing.

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