The final stage of drug addiction leads to :

Options

A. Drug immunity
B. Drug dependence
C. Drug resistance
D. All of these

Answer

### Step-by-Step Solution

1. **Understanding Drug Addiction**: Drug addiction is defined as a habitual physiological or psychological dependence on a substance. It occurs when individuals use drugs for purposes other than their intended clinical use, leading to abuse.

2. **Defining Addiction**: Addiction is characterized by a lack of voluntary control over the use of the substance. Individuals become dependent on the drug, meaning they cannot easily stop using it despite negative consequences.

3. **Tolerance Development**: With repeated use of drugs, the body develops a tolerance. This means that the individual needs to consume larger doses of the drug to achieve the same effects that were previously felt with smaller doses.

4. **Increased Dosage**: As tolerance increases, the individual may start increasing their drug intake. For example, if a person initially takes 1 gram of a drug, after some time, they may need to increase the dosage to 2 grams or more to feel the desired effects.

5. **Psychological Attachment**: Drug addiction also involves a psychological attachment to the effects of the drug, such as euphoria. This attachment reinforces the behavior of continued drug use.

6. **Dependence**: The final stage of drug addiction is characterized by dependence. Dependence manifests as withdrawal symptoms when the drug is not taken. These symptoms can include anxiety, sweating, nausea, and more.

7. **Withdrawal Symptoms**: If an individual does not take their regular dose of the drug, they may experience unpleasant withdrawal symptoms, which can compel them to use the drug again to alleviate these symptoms.

8. **Conclusion**: Therefore, the final stage of drug addiction leads to drug dependence, which is marked by a strong need to continue using the drug to avoid withdrawal symptoms.

### Final Answer
The final stage of drug addiction leads to **drug dependence**.

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