Proton pumps are used in various ways by members of every domain of organisms: Bacteria,Archaea,and Eukarya.What does this most probably mean?

A)Proton pumps must have evolved before any living organisms were present on Earth.
B)Proton gradients across a membrane were used by cells that were the common ancestor of all three domains of life.
C)The high concentration of protons in the ancient atmosphere must have necessitated a pump mechanism.
D)Cells of each domain evolved proton pumps independently when oceans became more acidic.
E)Proton pumps are necessary to all cell membranes.