In STP calculations, which parameters in the configuration BPDU may be used to determine the port role?

In STP calculations, which parameters in the configuration BPDU may be used to determine the port role?
A . Root ID, Root Path Cost, Bridge ID, Designate Port ID, Bridge Port ID
B . BPDU Type, Root ID, Root Path Cost, Bridge ID
C . Root ID, Root Path Cost, Bridge ID, Port ID
D . Flags, Root Path Cost, Bridge ID, Port ID

Answer: C