Assertion : Diabetes insipidus is marked by excessive urination and too much thirst for water .
Reason : Anti-diuretic hormone (ADH) is secreted by the posterior lobe of pituitary gland .

Options

A. If both Assertion and Reason are true and the Reason is the correct explanation of the Assertion, then mark a.
B. If both Assertion and Reason are true but the Reason is not the correct explanation of the Assertion, then mark a.
C. If Assertion is true statement but Reason is false, then mark c.
D. If both Assertion and Reason are false statements, then mark d.

Answer

**Step-by-Step Solution:**

1. **Understanding the Assertion:**
- The assertion states that "Diabetes insipidus is marked by excessive urination and too much thirst for water."
- This is true because diabetes insipidus is characterized by the production of large volumes of dilute urine, leading to increased thirst (polydipsia) as the body tries to compensate for the loss of water.

2. **Understanding the Reason:**
- The reason states that "Anti-diuretic hormone (ADH) is secreted by the posterior lobe of the pituitary gland."
- This statement is also true. ADH, also known as vasopressin, is indeed produced in the hypothalamus and released from the posterior pituitary gland. Its primary function is to regulate water balance in the body by promoting water reabsorption in the kidneys.

3. **Analyzing the Relationship:**
- To determine if the reason is a correct explanation for the assertion, we need to see if the assertion logically follows from the reason.
- The assertion is about the symptoms of diabetes insipidus, while the reason explains where ADH is secreted. Although both statements are true, the reason does not directly explain why diabetes insipidus leads to excessive urination and thirst.

4. **Conclusion:**
- Since both the assertion and reason are true, but the reason does not provide a correct explanation for the assertion, the correct option is that both are true but the reason is not a correct explanation for the assertion.

**Final Answer:**
Both assertion and reason are true, but the reason is not a correct explanation for the assertion.

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