Which question is focused and answerable enough to be considered an effective research question?

Is immigration a positive thing?

Who benefited most from the Immigration and Nationality Act of 1965?

How many immigrants gained US citizenship?

How many Chinese immigrants live in the US?

Is immigration a positive thing?

Explanation:

A good research question should required original data, formation of various sources of data, interpretation and/or argument to provide an answer. Thus, the answer to the research question should have discussion and interpretation of data that was gathered, and not just be a simple statement of fact.

Hence, the question that is focused and answerable enough to be considered an effective research question is "Is immigration a positive thing?"This is because to answer will require original data to be gathered from various sources, and then interpretation of those data, to provide answers.

The rest of the options in the questions only required answers that are simple statement of fact.