You can become a nurse for any reason. You could be an assistant to a very famous doctor and get great tips. You could help people with the experience fro of your job. You could help your family without being in a hospital. You could be a great example for children, You could inspire them to be like you when you get older. You would get paid fairly. You could even get enough experience to become a doctor! Nurses are important parts of people's lives which is why you could become one. Without nurses who would hand the doctors the tools they need? correct them? tell them what's wrong with the patient? That is the reason you could want to be a nurse.
C. How long does it take to travel from the Earth to the moon?
This is the weakest research question because it can be easily answered. According to a 2 second Google search, it takes about 3 days for a spacecraft to reach the moon from Earth. This question does not allow for a lot of research for development into an essay. Options A, B and D all have a variety of possibilities that would allow for a multi-paragraph essay with significant topic development.