If you are given the job of adding hydraulic fluid to a mooring winch, and are not certain

If you are given the job of adding hydraulic fluid to a mooring winch, and are not certain as to the type of fluid to use, you should _____.

A.add fluid that is the same color as the fluid in the reservoir

B.add turbine oil because it is always a good substitute

C.add any oil that has the same viscosity as the hydraulic fluid

D.check the winch manufacturers instruction book

请帮忙给出正确答案和分析，谢谢！