A Project Manager is challenged because she spends too much time on the staffing management plan defining how the resources will be released. To explain why release criteria  are important, he/she gives the following arguments, which one is not appropriate

a) It reduces cost

b) It helps us to know who is doing what

c) It increases team morale

d) It enables the next projet team to acquire the resource

Please suggest what could be the right answer

The answer says b, which i am perplexed.