Each Helium Atom Created Through the Proton-Proton Chain, Illustrated in the Figure

Each helium atom created through the proton-proton chain, illustrated in the figure below, is made up of two protons and two neutrons.How many neutrons and protons are required as inputs to the proton-proton chain?

A) 2 neutrons, 2 protons
B) 0 neutrons, 6 protons
C) 6 neutrons, 0 protons
D) 4 neutrons, 0 protons
E) 3 neutrons, 3 protons