How Does Being Specific Help You Manage Your Time

How does being specific help you manage your time?

A) Having details regarding the amount of work needed will let you precisely estimate the time required to accomplish each part of your task.
B) It doesn't: You will spend more time calculating all the aspects than you would if you just took action.
C) If you know how much time something will take,you know when you absolutely must begin to finish by the deadline,thus allowing you to do something else until that point.
D) You will be able to allot an exact amount of time to use,including travel time,so you will never have to use more than the time you have set aside.