What does the word "argument" mean in CR questions

[750plus]

Dear Members,

I have a query regarding CR questions asked in GMAT

I have seen the word "argument" in almost every other question of CR, but I am unable to conclude whether it refers to the "CONCLUSION" only OR it refers to the "PREMISES" OR something else altogether.

Example:
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?

Here the word "Argument" does not mean conclusion

WHEREAS

Most of the questions where it asks to Strengthen, Weaken the argument, it do refers to the CONCLUSION.

Please clarify.

PS: The question posted above as an example is one of the questions from GMAT Prep.

[RonPurewal]

The argument is the whole thing——the conclusion together with all of the stuff that supports it.

When you "weaken an argument", you're not necessarily attacking the conclusion itself. What you're always doing, though, is weakening the integrity of the reasoning used to reach that conclusion.
In other words, you're not really concerned with showing that the conclusion itself is false. You're concerned with showing that this particular argument[i] is [i]a bad way to try to show that it's true.

It's a lot like the job of a defense lawyer. You don't actually have to show that your client is innocent; you just have to show that the prosecution's case against your client is a bad case.