In a study of honesty conducted in various retail stores, customers who paid in cash and received change were given an extra dollar with their change.
Evidence
Customers who paid in cash at stores and received change were given an extra dollar with their change.
Few people who received an extra dollar returned it.
Conclusion (so)
Among those who received an extra dollar, most behaved dishonestly.
Evaluate
This argument attempts to explain a curious fact: when people received an extra dollar, why did so few of them return it?
By claiming that most of these people behaved dishonestly, the argument assumes that nothing else caused these people to keep the extra dollar. There are actually a number of reasonable explanations that have nothing to do with dishonesty. The argument never addresses any of these alternative explanations. Based just on the evidence we're given, there's no way we can be sure that any of these people behaved dishonestly.
This type of question isn't extremely common in LR, so it's important to clearly understand what the question is asking and what to expect in the answer choices. The answer choices are all questions that can be answered with a short, factual answer. These will often be questions that can be answered with "yes" or "no."
We need to think about a possible answer to each question, and consider what effect the answer would have on the argument. For example, if the answer to one question is "yes" that might strengthen the argument; however if the answer to that same question is "no" that might weaken the argument.
Goal
One answer choice will pose a question that has a noticeable impact on the argument. The answer choice which poses that question will be the correct answer choice. The other questions will have much less impact, and possibly even no impact.