On a Neutron Number Versus Proton Number Plot, the Nucleus ${ }_{+1}^{0} e$

On a neutron number versus proton number plot, the nucleus of oxygen-15 lies below the belt of stability. In the radioactive decay of oxygen -15, what subatomic particle is emitted

A) ${ }_{+1}^{0} e$
B) ${ }_{0}^{1} n$
C) ${ }_{2}^{4} \mathrm{He}$
D) ${ }_{-1}^{0} e$
E) None of the above