Based on the Activity Network Pictured,what Is the Best Statement

Based on the activity network pictured,what is the best statement?

A) Before starting Activity C,Activity A and Activity B must be completed.
B) Before starting Activity D,Activity A and Activity B need to be completed.
C) Before starting Activity E,Activity A and Activity B need to be completed.
D) Before starting Activity C,Activity A and Activity D must be completed.