Very Interesting question...
I also picked C initially but B seems best among all the options.
Although B seems best, but there is still lil doubt in my mind:

B says "most men who are born in large cities live almost their entire lives within the city of their birth to remain close to their families"

1) What if most men who stays alomst entire life time in cities do not suffer from Baldness and other men (All -most) move to the location "elsewhere".

2) This option does not compare with "what happens "elsewhere""?
Do these people also stays their entire lifetime in their locations?

I also want to know that while reading the question of the pattern

" Conclusion, Evidence"
in which we have to Weaken the ARGUMENT....We should follow which one of these...

A) weaken the conclusion ?
B) weaken the evidence ?

Considering both in the mind before going to the choices takes considerable amount of time in eliminating the answer choices.

Durgesh has concentrated on evidence while childcguy has concentrated on the conclusion.
Pls suggest.

The choice B is not bulletproof and not much better than C.

For one, B says "most men who live in large cities" and not most men in general. Also, going by this logic, one can argue that it is the stressful lifestyle in cities that causes baldness. Isn't this the point that is supposed to be weakened?

Where did you get this question from?

Guys can anyone give a decent reason why C is not right.