Core planning processes have clear dependencies that require them to be performed in essentially the same order on most projects．Which of the following is the correct order as a portion of core planning processes? （　）
A．Scope planning, scope definition, activity sequencing, activity duration estimation
B．Scope definition, scope planning, activity definition, activity sequencing, activity duration estimation
C．Scope planning, scope definition, activity sequencing, activity definition, activity duration estimation
D．Activity duration estimation, scope planning, scope definition, activity definition, activity sequencing