[A]: Morphine is most effective analgesic.
[R]: It binds to the post synaptic membrane & blocks the binding of neuro transmitters

Options

A. If both A and R are true and R is the correct explanation of A
B. If both A and R are true but R is not the correct explanation of A
C. If A is true and R is false
D. If both A and R are false

Answer

### Step-by-Step Solution:

1. **Understanding Morphine**:
- Morphine is classified as an opioid and is derived from the opium poppy plant (Papaver somniferum). It is known for its potent analgesic (pain-relieving) properties.

2. **Role of Morphine in Pain Relief**:
- Morphine is commonly administered before and after surgical procedures to manage pain effectively. It is considered one of the most effective analgesics available.

3. **Mechanism of Action**:
- Morphine works by binding to specific receptors in the brain and spinal cord known as opioid receptors. This binding action alters the perception of pain.

4. **Blocking Neurotransmitter Binding**:
- When morphine binds to these receptors, it inhibits the release of neurotransmitters (such as acetylcholine) that are responsible for transmitting pain signals. This means that the pain signal does not reach the brain effectively, leading to reduced pain sensation.

5. **Conclusion**:
- The statement [A]: "Morphine is the most effective analgesic" is true, and the reasoning [R]: "It binds to the post synaptic membrane & blocks the binding of neurotransmitters" accurately describes how morphine functions to relieve pain.

### Final Answer:
- Both statements A and R are correct. Morphine is indeed the most effective analgesic, and it works by binding to receptors and blocking neurotransmitter action, which prevents pain signals from being transmitted.

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