求助：句子作用题中consideration与assumption区别是什么呢？

libbymark

GWD1-Q22:
City Official:  At City Hospital, uninsured patients tend to have shorter stays and fewer procedures performed than do insured patients, even though insured patients, on average, have slightly less serious medical problems at the time of admission to the hospital than uninsured patients have.  Critics of the hospital have concluded that the uninsured patients are not receiving proper medical care.  However, this conclusion is almost certainly false.  Careful investigation has recently shown two things:  insured patients have much longer stays in the hospital than necessary, and they tend to have more procedures performed than are medically necessary.
In the city official’s argument, the two boldface portions play which of the following roles?
The first states the conclusion of the city official’s argument; the second provides support for that conclusion.
The first is used to support the conclusion of the city official’s argument; the second states that conclusion.
The first was used to support the conclusion drawn by hospital critics; the second states the position that the city official’s argument opposes.
The first was used to support the conclusion drawn by hospital critics; the second provides support for the conclusion of the city official’s argument.
The first states the position that the city official’s argument opposes; the second states the conclusion of the city official’s argument.
我知道答案选E哈，只是搞不清assumption与consideration的区别，望NN解答，谢谢啦！！