______ is a CNS stimulant as it interferes with the transport of the neuro-transmitter, dopamine.

Options

A. Valium
B. Barbituarate
C. Cocaine
D. Opium

Explanation

**Step-by-Step Solution:**

1. **Identify the Question:** The question asks for a CNS (Central Nervous System) stimulant that interferes with the transport of the neurotransmitter dopamine.

2. **Recall the Function of Dopamine:** Dopamine is a neurotransmitter that plays several important roles in the brain, including the regulation of mood, reward, and pleasure.

3. **Understand CNS Stimulants:** CNS stimulants are substances that increase brain activity, leading to increased alertness, attention, and energy.

4. **Consider Known CNS Stimulants:** Some common CNS stimulants include cocaine, amphetamines, and certain prescription medications.

5. **Focus on Dopamine Transport:** The question specifies that the stimulant interferes with the transport of dopamine. This means it affects how dopamine is reabsorbed in the brain.

6. **Evaluate Cocaine's Mechanism:** Cocaine is known to block the dopamine transporter, which prevents the reuptake of dopamine into the presynaptic neuron. This blockage leads to an accumulation of dopamine in the synapse.

7. **Determine the Effects of Cocaine:** The buildup of dopamine in the synapse contributes to the pleasurable effects associated with cocaine use, which is a characteristic of its stimulant properties.

8. **Choose the Correct Answer:** Based on the above analysis, the CNS stimulant that interferes with dopamine transport is cocaine.

**Final Answer:** Cocaine

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