Principles and rules of classification are studied under

Options

A. Systematics
B. Classification
C. Taxonomy
D. Nomenclature

Answer

To solve the question regarding the principles and rules of classification, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Question**: The question asks about the study of principles and rules of classification in biology. We need to identify the correct term that encompasses these principles and rules.

2. **Review the Options**:
- **Option 1: Systematics** - This refers to the study of the diversity of organisms and their evolutionary relationships. While it involves classification, it is broader and not solely focused on the rules of classification.
- **Option 2: Classification** - This term generally refers to the act of grouping organisms based on similarities and differences. However, it does not specifically refer to the principles and rules.
- **Option 3: Taxonomy** - This is the science of naming, describing, and classifying organisms. It includes the principles and rules of classification.
- **Option 4: Nomenclature** - This specifically refers to the naming of organisms, which is a part of taxonomy but does not encompass the entire classification system.

3. **Identify the Correct Answer**: Based on the definitions, the term that specifically relates to the principles and rules of classification is **taxonomy**.

4. **Conclusion**: Therefore, the correct answer to the question is **Option 3: Taxonomy**.