correct answer is D. How does learning another language affect elementary school students’ overall academic success?
Step-by-step explanation:
A research question refers to the question that guides a complete process or research that is the process of getting information to understand more deeply a situation or phenomenon. This implies, in the case you want to research bilingual education in elementary school an appropriate question should focus on bilingual education in the context of elementary school and also in a specific aspect that of it that is relevant and requires information to be understood.
Considering this, the most effective question is "How does learning another language affect elementary school students’ overall academic success?" because this focus on the topic and also through this the phenomenon of bilingual education can be understood more deeply. Also, other options do not focus on bilingual education in elementary school or do not explore the topic in a deep or complex way.