The study of theory, practice and rules of classification of living and extinct organisms is called

Options

A. Ecology
B. Taxonomy
C. Morphology
D. Physiology

Explanation

The study of theory, practice, and rules of classification of living and extinct organisms is called **taxonomy**.

### Step-by-Step Solution:

1. **Understanding the Question**: The question asks for the term that refers to the study of classification of both living and extinct organisms.

2. **Identifying Key Concepts**: The key concepts in the question are "study," "theory," "practice," "rules," "classification," "living organisms," and "extinct organisms."

3. **Exploring Related Terms**:
- **Ecology**: This term refers to the study of interactions between organisms and their environment, which is not what the question is asking.
- **Morphology**: This refers to the form and structure of organisms, not specifically classification.
- **Physiology**: This involves the study of the functions of living organisms and their parts, which is also not relevant to classification.

4. **Identifying the Correct Term**: The term that encompasses the study of classification, including the rules and practices for categorizing living and extinct organisms, is **taxonomy**.

5. **Conclusion**: Therefore, the correct answer to the question is **taxonomy**.