Awkward sentence...GMAT Prep

GMAT is all about giving most accurate answers in the given options. Sometimes, the sentence may convey a logical meaning and sometimes it may not.
Lets discuss each one by one:

1. Ignore it. Ability is singular, but author uses HAVE, which is wrong.
2. Ability can not become accurate. Ignore it again.
3.
4. two reasons for this options to be wrong...one is the use of LIKE instead of such as, and "accurate in ability" is not correct.
5. usage of "Ability don't provide" is wrong.

Hence, by POE approach, 3 is the best answer.

"Scientists have become ever more able to provide" doesn't exactly sound awkward, G'rant, but I think what is making you hesitate on that one is that it is long. The main idea of the phrase is obscured by information that is extraneous when you are trying to parse a sentence grammatically.

For example, in the correct construction above, you have a simple subj (scientists), then a passive/imperfect verb (have become able-- this would be TOTALLY wrong in an essay or in business writing but works on the GMAT, I think you sense that) which is separated by the adjective phrase "ever more".

In the end, however it is still the best answer. Pahwa's POE analysis shows that.