Which of the following statements is correct for the design and installation of diesel engine cooling water systems?（）

A.An alarm device with audible and visible signals is required for all cooling water systems
B.Propulsion engines with bores over 200 mm are to be fitted with cooling water jackets
C.Each totally enclosed cooling system shall be provided with a suitable head tank
D.Drain cocks are to be provided at the lowest points of all cylinder water jackets