Three kingdom system of classification was proposed by

Options

A. Haeckel
B. Linnaeus
C. Stanier
D. Copeland

Answer

To answer the question "Three kingdom system of classification was proposed by", we can follow these steps:

### Step-by-Step Solution:

1. **Understanding the Question**: The question asks for the name of the scientist who proposed the three kingdom system of classification.

2. **Identifying the Options**: The options provided are Haeckel, Linnaeus, Stennaier, and Copeland.

3. **Recalling Classification Systems**:
- Linnaeus is known for the two kingdom system of classification (Plantae and Animalia).
- Haeckel proposed the three kingdom system in 1866, which includes Animalia, Plantae, and Protista.
- Copeland and Stenner proposed the four kingdom system of classification.

4. **Selecting the Correct Answer**: Since Haeckel is the one who introduced the three kingdom system, the correct answer is Haeckel.

5. **Final Answer**: The three kingdom system of classification was proposed by Haeckel.