The sequence of parts in a generally used fuel oil supply system for a main engine is （）
(1)tanks in the double bottom
(2)centrifuges
(3)service tank
(4)settling tank
(5)viscosity regulator

A.(1)-(2)-(4)-(3)-(5)
B.(1)-(4)-(2)-(3)-(5)
C.(1)-(3)-(2)-(4)-(5)
D.(1)-(5)-(4)-(2)-(3)