The correct answers are A. Not too broad, B. Narrow in focus and C. Applicable to the topic
Step-by-step explanation:
A research question is one of the most important elements in research because this guides all the process. Due to this, a good research question only addresses one issue or has a specific focus; besides this, a good question can be answered and is relevant or applicable to the topic because it addresses important issues that have not been researched. Moreover, a good question avoids topics or issues that are too broad, have been answered or cannot be answered. Thus, "not too broad", "narrow in focus" and "applicable to the topic" are characteristics of good research questions.