Where D.C. motor of H.P. 12 or more requires frequent starting, stopping, reversing and speed control$?

Where D.C. motor of H.P. 12 or more requires frequent starting, stoppi

1.	Where D.C. motor of H.P. 12 or more requires frequent starting, stopping, reversing and speed control$?
A.	Drum type controller is used
B.	Three point starter is used
C.	Four point starter is used
D.	All above can be used
Answer» B. Three point starter is used