Answer: option B) peristaltic contractions
Explanation:
The ductus deferens, also known as sperm duct is a narrow tube which lead from the epipidymis to the seminal vesicle. It allows sperm cells to move along it by a rhythmic shortening and lengthening of its muscular walls - known as peristaltic contraction.
Thus, it is due to peristaltic contractions