Match List-I with List - II and choose the correct answer from the options given below.

List - I	List - II
(a) Allen's Rule	(i) Kangaroo rat
(b) Physiological adaptation	(ii) Desert lizard
(c) Behavioural adaptation	(iii) Marine fish at depth
(d) Biochemical adaptation	(iv) Polar seal

To match the concepts in List-I with the organisms/examples in List-II, let us analyze each term step-by-step:

1. (a) Allen's Rule: This rule states that mammals from colder climates generally have shorter ears and limbs to minimize heat loss. The polar seal has a thick layer of fat (blubber) and reduced extremity sizes/surface area to adapt to extreme cold, which is a classic example matching Allen's Rule. Therefore, (a) matches with (iv).
2. (b) Physiological adaptation: This refers to internal systematic responses of an organism to environmental stimuli. The kangaroo rat in North American deserts is capable of meeting all its water requirements through its internal fat oxidation (where water is a byproduct) and has the ability to concentrate its urine to a minimal volume. This is a physiological adaptation. Therefore, (b) matches with (i).
3. (c) Behavioural adaptation: This involves actions or behaviors that organisms perform to survive in their environment. The desert lizard lacks the physiological ability to cope with high temperatures, so it manages its body temperature active-behaviorally by basking in the sun to absorb heat when its body temperature drops, and moving into the shade when the ambient temperature starts increasing. Therefore, (c) matches with (ii).
4. (d) Biochemical adaptation: This involves biochemical changes, enzymes, or metabolic adjustments at the molecular level. Marine fishes living at great depths in the ocean experience crushing hydrostatic pressures. They possess specialized biochemical adaptations (such as pressure-resistant proteins and osmoprotectants) to survive and function normally under high pressure. Therefore, (d) matches with (iii).

Combining all the correct matches, we get:
(a) - (iv)
(b) - (i)
(c) - (ii)
(d) - (iii)

Thus, the correct option is a - iv, b - i, c - ii, d - iii.