Explanation/Reference:
For Fixed Duration & Units, the duration and units remain constant as the units/time are changed. Use this
duration type when the activity must be completed within a fixed time period and the total amount of work
is fixed.
Incorrect answers:
A: Fixed Units - Used when costs/work effort is a limiting factor. Use this duration type when the total
amount of work (costs or units) is fixed, and increasing resources can decrease the duration. In this case,
if you update the duration or units/time, the units remain constant.