Two identical metallic spheres, labelled A and B, carry excess charges of +1uC (sphere A) and +3UC(sphere B).

Which of the following must be true?

Each sphere has more electrons than protons.

Each sphere has more protons than electrons.

The spheres will attract each other.

If they touch and the excess charge redistributes, the total quantity of excess charge will decrease.

Each sphere has more protons than electrons.