Reflex action involves

Options

A. medulla oblongata
B. cerebellum
C. optoc lobe
D. spinal cord

Answer

### Step-by-Step Solution:

1. **Understanding Reflex Action**: Reflex action is an involuntary and rapid response to a stimulus. It is a protective mechanism that helps organisms respond quickly to harmful situations.

2. **Identifying the Components**: Reflex actions involve specific components:
- **Stimulus**: The event that triggers the reflex (e.g., touching a hot surface).
- **Receptor**: Sensory neurons that detect the stimulus.
- **Afferent Pathway**: The pathway that carries sensory information to the spinal cord.
- **Integration Center**: The spinal cord processes the information and generates a response.
- **Efferent Pathway**: The pathway that carries the response from the spinal cord to the effector (muscles).
- **Effector**: The muscle or gland that performs the response (e.g., pulling the hand away).

3. **Analyzing the Options**: The question provides four options regarding which part of the nervous system is involved in reflex actions:
- **A. Medulla Oblongata**: Involved in autonomic functions but not primarily in reflex actions.
- **B. Cerebellum**: Primarily involved in coordination and balance, not reflex actions.
- **C. Optic Lob**: Related to vision, not reflex actions.
- **D. Spinal Cord**: The correct answer, as it is the main center for processing reflex actions.

4. **Conclusion**: Based on the analysis, reflex actions primarily involve the spinal cord, which processes the sensory information and generates a motor response without the need for conscious thought.

### Final Answer:
The correct answer is **D. Spinal Cord**.

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