Two hydrogen nuclei repel one another due to the positive charges of the protons within them. at some separation distance this repulsion is overcome and the hydrogen nuclei can fuse to form helium. what force allows two protons to "stick" together? a) gravity b) electromagnetism c) weak nuclear force d) strong nuclear force

The answer to your question is D) Strong nuclear force

Explanation:

In nature, there are four fundamental interactions: electromagnetism, gravitation, weak nuclear force and strong nuclear force.

The Strong nuclear force is responsible for binding protons and neutrons to form a new nucleus.

Weak nuclear force is responsible for radioactive decay which means splitting nucleus.