What happens to the decaying proton during positron emission?

a
The proton decomposes into a neutron that stays in the nucleus and a positron that is ejected from the nucleus.
b
The proton decomposes into an electron that stays in the nucleus and a neutron that is ejected from the nucleus.
c
The proton decomposes into a neutron that stays in the nucleus and an electron that is ejected from the nucleus.
d
The proton decomposes into an electron that stays in the nucleus and a positron that is ejected from the nucleus

c

The proton decomposes into a neutron that stays in the nucleus and an electron that is ejected from the nucleus.