A project manager finds that a particular activity has a slack of 1 week when the activity is presented in a network diagram in CPM (Critical Path Method based on a deterministic model). What statement is correct?

a. “if the activity is finished 1 week earlier, it becomes critical”

b. “if the activity is delayed by 1 week, it becomes non-critical”

c. “if the activity is delayed by 1 week, it becomes critical”

d. the activity can never become critical regardless of the delay

e. the activity can never become non-critical regardless of the delay.