Which of the following drug interferes with dopamine & produce euphoria :- A Benzodiazapine  B Hashish  C LSD       D Coca alkaloid

To determine which of the given drugs interferes with dopamine and produces euphoria, we can analyze each option in terms of its pharmacological effects on the brain's reward system.

1. A. Benzodiazepine - These drugs primarily act on the GABA-A receptor to produce sedative and anxiolytic effects, rather than directly influencing the dopamine system. They do not produce significant euphoria.

2. B. Hashish - Hashish contains cannabinoids, particularly THC, which can affect the dopamine system and induce feelings of euphoria. While it does interact with dopamine, it's not primarily known for this mechanism.

3. C. LSD - Lysergic acid diethylamide primarily works on serotonin receptors rather than the dopamine system. Although it can induce altered perceptions and euphoria, it doesn’t primarily act through dopamine pathways.

4. D. Coca alkaloid - Cocaine (a notable coca alkaloid) acts as a strong stimulant by blocking the reuptake of dopamine in the brain, leading to increased levels of dopamine in the synaptic cleft. This results in significant euphoria as part of its psychoactive effects.

Conclusion

The drug that specifically interferes with dopamine and produces euphoria among the choices given is D. Coca alkaloid.