配件实行寿命管理，大修后的普通197726型轴承使用时间满5年（或50万km）必须报废。

Which statement is TRUE concerning radiotelephones on board towing vessels?（）

A.There cannot be a radiotelephone located anywhere except in the wheelhouse

B.The officer in charge of the wheelhouse is considered to have the radiotelephone watch

C.Only distress messages may be transmitted over channel 13

D.Only the Master of the vessel is allowed to speak over the radiotelephone