Answer:
By preventing preventing sperm from enter into semen.
Explanation:
Vasectomy is the surgical method to make the male sterile. In this sterilization method, the vas deferens is tied or part of it cut inside the scrotum. This blocks the transport of male gamete or sperm along with semen into the urethra. Due to this method, the male semen is devoid of sperm. Thus a male can't fertilize an egg of the female.