A Critical Path Network (CPM/PERT) helps the engineer focus on critical activities, reallocate resources from noncritical leads to critical ones, and avoid project-wide delays—i.e., all of the above.

Introduction / Context:
Critical Path Method (CPM) networks distinguish activities that directly control the project duration (critical) from those with float (noncritical). Recognizing this allows targeted control and proactive risk management.

Given Data / Assumptions:

• Critical path activities have zero total float.
• Noncritical activities possess float and may be ahead of plan.
• Resource shifting is possible within organizational constraints.

Concept / Approach:
Network analysis computes earliest and latest times and derives floats. Activities on the longest path (critical path) determine the project finish date. Any delay on this path delays the entire project; hence attention, monitoring, and resources should prioritize these activities.

Step-by-Step Solution:
1) Identify critical activities by zero float.2) Monitor them more frequently and assign experienced crews/resources.3) If noncritical tasks are ahead or comfortably within float, shift resources temporarily to critical tasks.4) Maintain vigilance: preventing slippage on critical activities prevents project slippage.

Verification / Alternative check:
Update the network periodically; if floats shrink or change, priorities must adjust. Earned-value or progress indices can cross-check that attention is indeed focused where schedule risk is highest.

Why Other Options Are Wrong:

• Options A, B, and C are each individually correct; selecting only one is incomplete.
• Therefore, the inclusive choice is the accurate answer.

Common Pitfalls:

• Overcommitting resources to noncritical tasks because they are easier to complete.
• Failing to recalculate floats after progress updates, leading to stale priorities.

Final Answer:
all the above.