Angiotensin converting enzyme (ACE) converts angiotensin I into angiotensin II. ACE inhibitors should not be given to a person with severe loss of blood because:

A. These will increase renal tubular K+ excretion.
B. These will relax smooth muscles in the arteries.
C. These will reduce aldosterone secretion and thereby prevent water retention.
D. These will decrease renal tubular NaCl and water excretion.

Which one of the following options represents the combination of correct reasons?

Correct option is C

EXPLANATION-

Option A:
ACE inhibitors do not increase renal tubular potassium excretion; instead, they tend to increase serum potassium because aldosterone secretion is reduced, which decreases potassium excretion. So this statement is incorrect.

Option B:
ACE inhibitors cause vasodilation by reducing angiotensin II, leading to relaxation of smooth muscles in arteries. This statement is correct.

Option C:
By reducing angiotensin II, ACE inhibitors decrease aldosterone secretion. Reduced aldosterone leads to less sodium and water retention, which can lower blood volume. This statement is correct.

Option D:
This option states ACE inhibitors decrease NaCl and water excretion which is incorrect; they actually cause increased excretion of sodium and water due to decreased aldosterone.

So, the correct reasons are B and C