Respuesta :
That which must be true for a research question to be considered effective is: The question must have a single focus for research from valid sources.
For a research question to be considered effective, it must have a single focus.
That means that it must be specific in the question that it answers. This will make it easier for the readers to follow through on the findings.
Also, the primary and secondary sources from where the findings are made should be valid so that the content will be reliable.
So, option A meets the requirement of an effective research question.
Learn more about effective research questions here:
https://brainly.com/question/1442162