After erection, semen release is a two-step process.
which process mixes the fluid components of the semen, via coordination of peristaltic contractions in several male reproductive structures?

Emission

Explanation:

Semen contains sperm and the secretions released by the accessory sex glands such as seminal vesicle and prostate gland. Before the ejaculation of semen, the muscles of the epididymis, ductus deferens, seminal vesicles, ejaculatory ducts, and prostate gland exhibit peristalsis. This results in the release of the secretions from the accessory glands and reproductive duct into the urethra. Since semen is present in the urethra, a small volume of semen is discharged even before ejaculation during emission.