Final answer:
A research question for an informative essay should be open-ended, consequential, and answerable.
Step-by-step explanation:
A research question for an informative essay should meet several criteria. It should have an open-ended answer that allows for multiple plausible responses. It should also be consequential, meaning that the outcome of the debate around the question should matter. Lastly, it should be answerable, meaning that existing source material can be consulted to provide evidence-based answers.