The nucleus of any atom requires a strong force to hold it together. this strong force is required because

a)
the nucleus of any atom is so small.

b)
protons and neutrons repel each other.

c)
positive protons in the nucleus repel each other.
eliminate

d)
the charges of the protons and the electrons cancel each other out.

b

Explanation:

positive protons in the nucleus repel each other.

note-Of the four fundamental forces in the universe, the strong force is just that, the strongest. It is found in the nucleus and it holds the nucleus together since positive protons in the nucleus repel each other as expected due to the law of attraction.

they are non-matter

explanation:

they are non-matter. basically, any type of energy or any abstract concept is an example of something that does not matter. other examples include dreams, magnetism, radio, and hate