The drugs obtain from plant is:

Options

A. caolin
B. insulin
C. magnesium sulphate
D. morphine

Explanation

To determine which drug is obtained from a plant, we can analyze the options provided:

1. **Kaolin**: This is a type of clay that is formed naturally and is not derived from plants. Therefore, it is not the correct answer.

2. **Insulin**: Insulin is a hormone produced by the pancreas in animals, particularly in humans. It is not derived from plants, so this option is also incorrect.

3. **Magnesium Sulfate**: This is a chemical compound that is synthesized and does not come from plant sources. Hence, it is not the correct answer.

4. **Morphine**: Morphine is a well-known drug that is derived from the opium poppy plant (Papaver somniferum). It acts on the nervous system, primarily as a pain reliever, and is commonly used in medical settings, especially during surgeries.

Based on the analysis of the options, the drug obtained from a plant is **morphine**.

### Steps:
1. **Identify the options**: List all the drugs provided in the question.
2. **Analyze each option**: Determine whether each drug is derived from a plant or not.
3. **Conclude with the correct answer**: Identify the drug that is confirmed to be obtained from a plant.