Assertion:Reflex arc comprises of at least one afferent neuron, one efferent neuron and a part of PNS.
Reason:The efferent neuron receivers signal from a sensory organ and transmits the impulse via a ventral nerve root into the PNS.

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.

Explanation

### Step-by-Step Solution:

1. **Understanding the Assertion**:
- The assertion states that a reflex arc consists of at least one afferent neuron, one efferent neuron, and a part of the peripheral nervous system (PNS).
- A reflex arc indeed includes an afferent neuron (sensory neuron), an efferent neuron (motor neuron), and connections to the PNS. However, the assertion is misleading because it does not specify the role of the central nervous system (CNS) in the reflex arc.

2. **Understanding the Reason**:
- The reason states that the efferent neuron receives signals from a sensory organ and transmits the impulse via a ventral nerve root into the PNS.
- This statement is incorrect because the efferent neuron does not receive signals from sensory organs; instead, it carries signals from the CNS to effectors (muscles or glands). The sensory signals are received by the afferent neuron, which transmits them to the CNS via the dorsal nerve root.

3. **Evaluating the Truth of the Statements**:
- Since the assertion contains inaccuracies regarding the components of the reflex arc and the roles of the neurons, it is false.
- The reason is also false because it incorrectly describes the function of the efferent neuron.

4. **Conclusion**:
- Both the assertion and the reason are false. Therefore, the correct option is that both assertion and reason are false.

### Final Answer:
Both assertion and reason are false.

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