Match List - I with List - II and choose the correct answer.

List - I	List - II
(a) Vaults	(i) Entry of sperm through Cervix is blocked
(b) IUDs	(ii) Removal of Vas deferens
(c) Vasectomy	(iii) Phagocytosis of sperms within the Uterus
(d) Tubectomy	(iv) Removal of fallopian tube

The correct option is a - (i) b - (iii) c - (ii) d - (iv).

To match List-I with List-II, let us analyze each contraceptive method and its function step-by-step:

(a) Vaults:
Vaults are hemispherical dome-shaped rubber barriers that are inserted into the female reproductive tract to cover the cervix during intercourse. They prevent pregnancy by physically blocking the entry of sperms through the cervix. Therefore, (a) matches with (i).

(b) IUDs (Intrauterine Devices):
Intrauterine Devices are inserted by medical professionals into the female uterus. These devices increase the phagocytosis (engulfing and destruction) of sperms by immune cells within the uterus, thereby inhibiting sperm motility and fertilization. Therefore, (b) matches with (iii).

(c) Vasectomy:
Vasectomy is a permanent surgical method of sterilization in males. During this procedure, a small portion of the vas deferens (the sperm duct) is removed or tied off to prevent sperm from entering the semen. Therefore, (c) matches with (ii).

(d) Tubectomy:
Tubectomy is a permanent surgical method of sterilization in females. During this procedure, a small part of the fallopian tubes is removed or tied off to prevent the transport of ova (eggs) and block fertilization. Therefore, (d) matches with (iv).

Matching the columns based on this analysis:
(a) Vaults → (i) Entry of sperm through Cervix is blocked
(b) IUDs → (iii) Phagocytosis of sperms within the Uterus
(c) Vasectomy → (ii) Removal of Vas deferens
(d) Tubectomy → (iv) Removal of fallopian tube

This corresponds exactly to the option: a - (i) b - (iii) c - (ii) d - (iv).