Match I with column II
`{:("Column "I, "Column "II), (a. " Capillaries", (i)" Valves"),(b." Veins", (ii)" Smooth muscles"),(c." Aorta", (iii)" Narrowest blood vessels"),(d." Tunica media", (iv)" Elastic artery"):}`
Select the alternative which shows the correct matching.

Options

A. a(iv), B(iii), c(i), D(ii)
B. a(iii), b(iv), c(ii), d(i)
C. a(iii), b(i), c(iv), d(ii)
D. a(ii), b(i), c(iv), d(iii)

Answer

To solve the matching question, we will analyze each item in Column I and find the corresponding item in Column II.

### Step-by-Step Solution:

1. **Capillaries (a)**:
- Capillaries are the smallest and thinnest blood vessels in the body.
- They are responsible for the exchange of gases, nutrients, and waste between blood and tissues.
- Therefore, capillaries match with **(iii) Narrowest blood vessels**.

2. **Veins (b)**:
- Veins carry blood back to the heart.
- They have valves to prevent the backflow of blood.
- Thus, veins match with **(i) Valves**.

3. **Aorta (c)**:
- The aorta is the largest artery in the body.
- It is classified as an elastic artery due to its ability to stretch and accommodate high blood pressure.
- Hence, the aorta matches with **(iv) Elastic artery**.

4. **Tunica media (d)**:
- The tunica media is the middle layer of blood vessels, primarily composed of smooth muscle.
- This layer is responsible for the contraction and relaxation of blood vessels.
- Therefore, tunica media matches with **(ii) Smooth muscles**.

### Summary of Matches:
- (a) Capillaries → (iii) Narrowest blood vessels
- (b) Veins → (i) Valves
- (c) Aorta → (iv) Elastic artery
- (d) Tunica media → (ii) Smooth muscles

### Final Matching:
- A → iii
- B → i
- C → iv
- D → ii

### Correct Option:
The correct matching is:
- (a) Capillaries - (iii) Narrowest blood vessels
- (b) Veins - (i) Valves
- (c) Aorta - (iv) Elastic artery
- (d) Tunica media - (ii) Smooth muscles