Assertion : Saliva secretion is a reflex action.
Reason : Saliva secretion is controlled by only brain and not the hormones.

Options

A. If both Assertion and Reason are true and Reason is correct explanation of Assertion.
B. If both Assertion and Reason are true but Reason is not 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 "Saliva secretion is a reflex action." This means that the process of saliva secretion occurs automatically in response to certain stimuli, such as the presence of food in the mouth. This is indeed true as saliva secretion is primarily controlled by the autonomic nervous system (ANS), which operates reflexively.

2. **Understanding the Reason**: The reason provided is "Saliva secretion is controlled by only the brain and not the hormones." To evaluate this, we need to consider how saliva secretion is regulated. While the brain does play a significant role in controlling saliva secretion, it is not the only factor involved. Hormones also influence saliva production.

3. **Analyzing the Role of Hormones**: Hormones like the antidiuretic hormone (ADH) and others can affect saliva secretion. For example, ADH helps regulate water balance in the body, which can indirectly influence the viscosity and amount of saliva produced. Therefore, the statement that saliva secretion is controlled solely by the brain is incorrect.

4. **Conclusion**: Since the assertion is correct (saliva secretion is indeed a reflex action), but the reason is incorrect (saliva secretion is also influenced by hormones), we can conclude that the assertion is true while the reason is false.

5. **Final Answer**: The correct answer is that the assertion is true, but the reason is false.