影响初馏塔顶压力因素：原油含水（电脱盐没开情况下）及原油性质变化；冷后温度变化：冷后温度高时塔顶压力上升；换热温度变化：换热温度高时，塔顶压力上升；空冷器入口阀开度大小：阀开度大，压力低。请回答初馏塔顶压力：控制范围、控制目标、相关参数、控制方式？

A．zero because Polly’s income didn’t changE．B．the change in Polly’s demand if her income is decreased by the change in the price of fruit times her old consumption of fruit．C．the change in Polly’s demand if her income is decreased by the total amount she used to spend on fruit．D．the change in Polly’s demand if her income is increased by the amount she used to spend on fruit．

A.CT
B.MRI
C.心电图
D.DSA