Assertion : Synaptic knob of axon has large number of synaptic vesicles.
Reason: Conduction of nerve impulse is always from axon to dendron.

Options

A. If both Assertion and Reason are true and assertion is correct explanation of Assertion
B. If both Assertion and Reason are true but Reason is not a 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 the synaptic knob of an axon has a large number of synaptic vesicles.
- This is true because synaptic vesicles are responsible for storing neurotransmitters, which are essential for transmitting signals between neurons.

2. **Understanding the Reason**:
- The reason provided states that the conduction of nerve impulses is always from axon to dendron (dendrite).
- This statement is partially misleading. While it is true that impulses travel from the axon of one neuron to the dendrites of another neuron, the term "dendron" is not commonly used in this context. The correct terminology should refer to "dendrites" or "postsynaptic neurons."

3. **Evaluating the Relationship**:
- The assertion is true, as synaptic knobs do contain many synaptic vesicles.
- The reason is also true, but it does not correctly explain the assertion. The conduction of nerve impulses does occur from axon to dendrite, but this does not directly relate to the presence of synaptic vesicles in the synaptic knob.

4. **Conclusion**:
- Since both the assertion and reason are true but the reason does not explain the assertion, the correct answer is that the assertion is true, and the reason is not a correct explanation of the assertion.

### Final Answer:
- The assertion is true, and the reason is not a correct explanation of the assertion.