You are correct that "almost always" doesn't mean "always", but wrong to fret about it too much. In the question, B is clearly a wrong answer - we cannot infer from the statements that driver's ed is the best way to reeducate drivers. it is presented as "a way", but is not compared to other methods.
I think your problem is less the handling of a single word here and there, and more to do with lack of confidence in your chosen answer. A is clearly a better answer, except for that little annoying part where "always almost" leaves some room for the remote possibility of reforming a driver. But the fact that our chosen answer seems to have a minor problem doesn't mean that we choose a clearly wrong answer. The correct answers are sometimes less than ideal, but are chosen for being the least worst of the answer choice presented. We choose A because B is clearly a worse answer.
It also means that we look for ways why A is indeed correct and the problem isn't really an issue:
The argument states that "Only if such drivers are
likely to be made more responsible drivers ". Since the later sentence says that a driver is always
almost impossible to reform, it means that while there's a remote chance of reforming a driver, this chance is
always remote - i.e. you will never find a driver that is
likely to be made a more responsible driver. Since no Driver thus meets the conditions for re-education, send them all to jail, which means that the argument as stated does indeed support A.
I have to say that this nitpicking is more LSAT and less GMAT. But the key here is to stand your ground and not let the question sway you. When going through the question, your initial reaction was probably: so according to this, the vast majority of drivers will go to jail". Look for an answer choice that says that or goes in that direction, and firmly eliminate those answer choices that are clearly wrong.
