Confuse, we are in the same boat.
The problem with boldface is that the minute we see boldfaced parts, we try to place them in context without fully understanding it's position.
My suggestion is that you treat the passage like a normal non-bold CR. Read the full argument and write down the premises, conclusion, sub-conclusion etc without paying any attention to the bold part.
Then read the question stem.
Move through answers one by one. In a particular answer choice, it would say First part is evidence and second part is conclusion etc. Once you have already classified each statement, one answer choice will perfectly fit.
If you want, register on e-gmat. They have a set of 20 boldface questions free for practice. If you are struggling with any question, post it here so that some of the members can work together and solve the problem. What say?
Vineesh,
Just telling you what I know and think. I am not the expert.
