Drugs obtained from plants are mostly
(a) Terpenes
(b) Alkaloids
(c) Lignin deposits
(d) None of the above

Options

A. Terpenes
B. Alkaloids
C. Lignin deposits
D. None of the above.

Answer

**Step-by-Step Solution:**

1. **Understanding the Question**: The question asks which type of compounds are mostly used as drugs obtained from plants. The options provided are terpenes, alkaloids, lignin deposits, and none of the above.

2. **Identifying Plant-Derived Drugs**: Many drugs used in medicine are derived from plant sources. These drugs can be classified into different categories based on their chemical structure and properties.

3. **Analyzing the Options**:
- **Option (a) Terpenes**: These are a large and diverse class of organic compounds produced by various plants. While some terpenes have medicinal properties, they are not the most common source of drugs.
- **Option (b) Alkaloids**: Alkaloids are a group of naturally occurring organic compounds that mostly contain basic nitrogen atoms. They are known for their pharmacological effects and are commonly used in medicine. Examples include morphine, quinine, and caffeine.
- **Option (c) Lignin deposits**: Lignin is a complex organic polymer found in the cell walls of plants, providing structural support. It is not typically used as a drug.
- **Option (d) None of the above**: This option suggests that none of the listed compounds are primarily used as drugs from plants, which is incorrect.

4. **Conclusion**: Based on the analysis, alkaloids are the most common type of compounds derived from plants that are used as drugs. Therefore, the correct answer is **(b) Alkaloids**.

**Final Answer**: (b) Alkaloids

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