In your project，there is：25% probability for $25000 profit．50% probability for $40000 profit，25% probability for $100000 profit．What is the expected profit in your project

A．$40000．

B．$50000．

C．$51250．

D．$53750．

合成开车过程中要经常检查氨分离器液位，防止液位突然上涨来不及调节，造成停车。