Final answer:
The cervical plexus supplies nerves to the posterior head and neck, as well as to the diaphragm.
Step-by-step explanation:
The subject of this question is Biology as it asks about nerve fibers and nerve plexuses in the human body.
In this question, option C) "Supplies the posterior body trunk" is correct. The nerve plexuses in the body are responsible for supplying different regions of the body with nerve fibers. The sacral plexus supplies the posterior leg, while the other plexuses supply different regions such as the arm, anterior leg, and head and neck.
For example, the sciatic nerve, which is part of the sacral plexus, supplies the posterior leg. It is formed by the combination of the tibial nerve and the fibular nerve.