The correct answer is D. All of the above.
A research problem is feasible only when it has utility and relevance, it is researchable, and it is new and adds something to knowledge.
A research problem has utility and relevance when it addresses a real-world issue or problem. It should be something that people care about and that could potentially make a difference in the world.
A research problem is researchable when it is possible to collect data and analyze it to answer the research question. The data should be available and accessible, and the methods used to collect and analyze the data should be sound.
A research problem is new and adds something to knowledge when it addresses a question that has not been answered before or when it provides a new perspective on a well-studied topic. The research should be original and contribute to the body of knowledge in the field.
If a research problem does not meet all of these criteria, it is not feasible to conduct research on it.