Which hypothesis led to discovery of the proton?

There is a positive charge in the nucleus

Explanation:

The concept was envisaged by Ernest Rutherford. He was a renowned scientist and chemist. In the hypothesis, he proposed that an atom must have a concentrated positive charge around the nucleus or in the nucleus that contains the atom's mass. He also suggested that the nucleus contains a particle with a positive charge that was called a proton.

the answer is c.the valence of the atoms combine .