A journalist recently noted that the Stanford Linear Accelerator Center superficially resembles the pipe-filled basement of a large apartment building, each pipe a conduit not for water, but for electrons traveling through it at near-light speed.

A each pipe a conduit not for water, but for electrons traveling through it
B each pipe a conduit not for water, but for electrons traveling through them
C all the pipes a conduit not for water, but for electrons traveling through them
D all the pipes a conduit not for water, but for electrons traveling through it
E every pipe a conduit not for water, but for electrons traveling through them

OA is A

Pls can an expert give a breakdown of the parallelism in this sentence?