a medium planet with an atmosphere. a star composed of carbon and nitrogen. a black hole that was once a star. a star composed of hydrogen and helium.
I am hesitating between 4 options to answer the following question, which option should I choose?
Question: What is at the center of our solar system?
Possibilities:
- a medium planet with an atmosphere.
- a star composed of carbon and nitrogen.
- a black hole that was once a star.
- a star composed of hydrogen and helium.

a star composed of hydrogen and helium.