An activity on the project network has a slack time of 0 days.
Which of the following is always true?
a. Increasing the activity time by 2 days will decrease project duration by 2 days.
b. Decreasing the activity time by 2 days will increase project duration by 2 days.
c. Decreasing the activity time by 2 days will decrease project duration by 2 days.
d. Increasing the activity time by 2 days will increase project duration by 2 days.
