All of the following are major spinal nerve plexuses except the ________ plexus.

A) lumbar
B) brachial
C) sacral
D) cervical
E) thoracic

During spermatogenesis, what are the first haploid cells produced?

A) primary spermatocytes
B) spermatogonium
C) spermatids
D) sertoli cells
E) secondary spermatocytes