Which of the following actions are stated in the correct order prior to loading or discharging cargo on a Ro-Ro vessel? （）

A. Lower the stern ramp，raise/open the stern door，turn on ventilation for cargo holds
B. Turn on ventilation for cargo holds，raise/open the stern door，lower the stern ramp
C. Turn on ventilation for cargo holds，lower the stern ramp，raise/open the stern door
D. Raise/open the stern door，lower the stern ramp，turn on ventilation for cargo hold