Assertion (A): Thrombin is the inactive form of prothrombin which is produced during blood coagulation.

Reason (R): Vitamin K, a fat-soluble vitamin, is essential for the production of prothrombin.

1. Both A and R are True
2. Both A and R are False
3. A is True and R is False
4. A is False and R is True

Assertion (A): Blood group 'AB' does not contain any antibody but contains both the antigens 'A' and 'B'.

Reason (R): In humans, WBCs have specific proteins on their surfaces. These proteins are called antibodies.

1. Both A and R are True
2. Both A and R are False
3. A is True and R is False.
4. A is False and R is True.

Assertion (A): Renal artery carries deoxygenated blood full of nitrogenous wastes.

Reason (R): Most of the arteries carry oxygenated blood, but there are exceptions.

1. Both A and R are True
2. Both A and R are False
3. A is True and R is False.
4. A is False and R is True.

Assertion (A): Efferent arteriole is wider than the afferent arteriole.

Reason (R): The difference in the size of the diameter of these arterioles creates a high pressure known as hydrostatic pressure. This pressure helps in the process of ultrafiltration through the glomerulus.

1. Both A and R are True
2. Both A and R are False
3. A is True and R is False.
4. A is False and R is True.