Given below are two columns. In Column I the names of four contraceptive devices are given and in Column II the modes of action of the contraceptives are given. Select the option where the contraceptive devices are correctly matched with their respective modes of action.

The correct option is P-ii, Q-iv, R-iii, S-i.

To understand why this is the correct match, let us analyze the mode of action for each contraceptive device listed in the columns:

1. P. Lippes loop matches with ii. Phagocytosis of sperms in uterus
Lippes loop is a non-medicated intra-uterine device (IUD) made of plastic (specifically double-S loop). Its presence in the uterus acts as a foreign body, stimulating a local inflammatory response. This response increases the phagocytosis (engulfing and destruction) of spermatozoa within the uterus, preventing them from reaching the fallopian tubes.

2. Q. Multiload 375 matches with iv. Makes cervix hostile to sperms
Multiload 375 is a copper-releasing IUD. Copper ions released by the device suppress sperm motility and fertilizing capacity. Along with this, the cellular changes induced in the uterus and cervix make the cervical environment hostile and barrier-like to sperm penetration, preventing successful fertilization.

3. R. Subcutaneous Norplant matches with iii. Causes thickening of cervical mucous
Norplant is a subcutaneous implant system consisting of small rods placed under the skin that slowly release synthetic progesterone (levonorgestrel). A major mechanism of action of progestin-only contraceptives is to increase the viscosity and thickness of the cervical mucus. This thickened mucus acts as a physical barrier that prevents sperms from entering the uterine cavity.

4. S. Saheli matches with i. Inhibition of ovulation
Saheli is a once-a-week non-steroidal oral contraceptive pill containing Ormeloxifene (also known as Centchroman). It acts as a Selective Estrogen Receptor Modulator (SERM). By competing with estrogen for binding sites in the uterus, it alters the endometrium and prevents implantation. It also interferes with the normal hormonal feedback loop, leading to the inhibition of ovulation.

Matching these together, we get:
• P → ii
• Q → iv
• R → iii
• S → i