Vikram -
I am glad you have asked this question so that I can write something that I have been thinking about. You know that correct answers to assumption questions are really very similar to correct answers to inference questions. In each case you really do want to avoid really strong statements, unless these are absolutely necessary.
For example, take an inference answer choice that says, "All who read my postings will earn a 700 on an actual administration of the GMAT this year." Wow!! That is hard to prove! Imagine the stimulus that would be necessary for this to be a correct inference answer. It would literally have to say these things. A better choice would be, "Reading Beat the GMAT postings offers you a chance for improvement." Much easier to prove.
The same holds true for assumption questions. What kind of assumption question would we need to have where the correct answer - the REQUIRED ASSUMPTION - is "All who read my postings will earn a 700 on an actual administration of the GMAT this year." What kinds of wild claims must have been made in the stimulus if the REQUIRED assumption is this?
You must be wary of two kinds of answer choices for assumption questions. 1) Answers that are too strong. Remember the answer choice is something that is REQUIRED. When will it be required that "ALL" or "NONE" have some property? If you come back later and write about your success on the GMAT and you tell us that you scored over 700 on the exam does your claim require that "ALL people score over 700?" Certainly not! It does require that it be "POSSIBLE to score over 700", which is a much weaker statement.
2) Be wary of answers that are too specific. Let's stick with the claim that you scored over 700 on the GMAT. Does this require that you scored 720? Or 730? or 790? No! Overly specific answers are very rarely good assumption answers.
A good assumption answer is often something that does not seem to do much as it is written. In other words, it seems quite weak if you ADD it to the argument. That is because the focus of assumption questions is not to ADD to the argument but to imagine what happens if we TAKE something AWAY from the argument.
Let's look at choice A and B from this argument.
Choice B) Is both to strong and too specific. "B) Domestic horses are genetically identical to wild horses." No I know that you are likely thinking that this is very helpful to your argument. No doubt it is, but that is not the point of an assumption question. The point is is the statement REQUIRED? So, is it absolutely required that these horses be genetically identical? NO!! This is WAY too strong and WAY too specific. In truth wild horses are usually a little smaller than domestic horses, the coloring is often different, too. Does this matter to the hooves? You and I are not genetically identical yet the same sorts of nutrition and exercise are generally good for each of us.
DO NOT THINK OF HOW NICE A CHOICE WOULD BE WHEN ADDED! YOU MUST THINK OF HOW BAD IT IS FOR YOUR ARGUMENT WHEN SOMETHING IS TAKEN AWAY.
Look at Choice A) "The conditions under which wild horses live play a role in creating strong hooves and avoiding lameness." Now what if this is not true? What if the conditions play no role whatsoever. What if the lameness is do to the fact that domestic horses live much longer - the way that few people would ever get cancer if we all died at age 30? Now this would definitely harm this argument! That is what you are looking for in an assumption question!
