A System of an Electron, a Proton, and a Neutron $\times$

A system of an electron, a proton, and a neutron has a net charge of

A) +1.6 $\times$ 10^-19 C.
B) -1.6 $\times$ 10^-19 C.
C) 3.2 $\times$ 10^-19 C.
D) zero.