Yes and no.
Straight questions such as your A vs B example could verge on shopping requests or at worst LMGTFY ones; neither of which are particularly constructive for this site.
However, if you have a particular problem that you need solving and research is going to be the only real way of solving it then you can request such research while outlining the actual problem you are having. For example if you are doing some work for a stakeholder who absolutely insists on having a Contact Us form with 25 different fields in it and the only way s/he can be convinced it's a bad idea is with some solid research then such a question would be OK, provided you specify the actual problem you have and explain why answers with research would be better.
Answers that have research attached are far more useful in general anyway, so in many cases it would go without saying that attaching some research to an answer is going to be better than not doing so.
Really, Stack Exchange is a repository for good questions and good answers. A request for a piece of research isn't really an interesting or useful question, but a question that explains a particular problem, requesting that some hard evidence be included in the answer is more beneficial and welcome.
Finally, be careful that you don't put people off answering. If you have a question and explicitly request that answers have to include research you may miss out on some valuable and interesting answers from people who can answer from experience but not from research.