For good reflex actions we require intact

Options

A. spinal cord
B. medulla oblongata
C. hypothalamus
D. cerebellum

Explanation

**Step-by-Step Solution:**

1. **Understanding Reflex Actions**: Reflex actions are defined as involuntary and spontaneous responses to external stimuli. They occur without conscious thought and are typically quick responses to certain stimuli.

2. **Identifying the Components of the Nervous System**: The main components involved in reflex actions include the spinal cord and various parts of the brain such as the medulla oblongata, hypothalamus, and cerebellum.

3. **Role of the Spinal Cord**: The spinal cord plays a crucial role in reflex actions. It acts as a pathway for signals between the body and the brain and is responsible for processing reflexes. For instance, when you touch a hot surface, sensory neurons send signals to the spinal cord, which then immediately sends signals to motor neurons to withdraw the hand.

4. **Excluding Other Options**:
- **Medulla Oblongata**: While it controls some autonomic functions, it is not primarily responsible for reflex actions.
- **Hypothalamus**: This part of the brain regulates homeostasis and is not directly involved in reflex actions.
- **Cerebellum**: This part coordinates voluntary movements and balance but does not control reflex actions.

5. **Conclusion**: Since reflex actions are primarily mediated by the spinal cord, the correct answer to the question is **spinal cord**.

**Final Answer**: For good reflex actions, we require intact **spinal cord**.

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