I would say d but I’m not sure
Answer:
Nuclear fusion
Explanation:
Nuclear fusion is the source of Sun's energy.. At the core where temperature and pressure are very high hydrogen atoms fuse into helium atom and release energy in the form of Gama rays.
The letter (d.) strong base or acid would be the most appropriate answer to the question above. An indicator is a strong base or acid. Indicators are strong base and acid because through this you can determine if a compound is acid or base with its color.
Viruses..................