As electrons are transferred down the ETC _________ are pumped into the _____________________________ which establishes an electrochemical gradient, and makes that space very (acidic/basic).

a) Protons, Mitochondrial Matrix, Acidic
b) Electrons, Endoplasmic Reticulum, Basic
c) Ions, Nucleus, Neutral
d) Neutrons, Cytoplasm, Alkaline