CPM requires

Answer: Option A

Correct Answer: A: Single time estimate
Let's break down why!
CPM stands for Critical Path Method.
It's a project management technique.
CPM focuses on activities with a fixed, known duration.
Think of it like this: you know exactly how long each task will take.
Therefore, CPM only needs a single time estimate for each activity.
Options B and C (Double and Triple time estimate) are related to PERT, another project management technique.
PERT deals with uncertainty and uses multiple time estimates.