Assertion:Aldosterone is polypeptide hormone and control the `Na^(+)` & `K^(+)` ratio in body.
Reason:- Aldosterone increase reabsorption of `Na^(+)`from plasma of blood and control its loss and increase loss of `K^(+)` in body fluid.

Options

A. If both assertion and reason are true and reason is the correct explanation of assertion
B. If both assertion and reason are true but reason is not the correct explanation of assertion
C. If assertion is true but reason is false
D. If both assertion and reason are false.

Answer

**Step-by-Step Solution:**

1. **Understanding the Assertion:**
- The assertion states that "Aldosterone is a polypeptide hormone and controls the Na+ & K+ ratio in the body."
- To evaluate this, we need to know the nature of aldosterone. Aldosterone is actually a steroid hormone produced by the adrenal cortex, specifically from the zona glomerulosa. Therefore, the assertion is incorrect because it misclassifies aldosterone as a polypeptide hormone.

2. **Understanding the Reason:**
- The reason states that "Aldosterone increases reabsorption of Na+ from plasma of blood and controls its loss and increases loss of K+ in body fluid."
- While it is true that aldosterone increases the reabsorption of Na+ and promotes the excretion of K+, the statement incorrectly implies that it reabsorbs Na+ from the plasma of blood. Aldosterone acts primarily on the renal tubules, where it reabsorbs Na+ from the filtrate (not directly from blood plasma) and facilitates the excretion of K+. Thus, the reason is also incorrect.

3. **Conclusion:**
- Since both the assertion and the reason are incorrect, the correct option is that both statements are false.

**Final Answer:**
- Both the assertion and the reason are incorrect.

---