Systematics is the

Options

A. Branch of biology concerned with evolutionary relationships among organisms
B. Branch of biology concerned with the scientific classification of organisms
C. Branch of biology concerned with the diversity of life
D. Branched of biology concerned with the study of multicellular organisms.

Answer

**Step-by-Step Solution:**

1. **Understanding Systematics**: Systematics is a branch of biology that combines two key components: taxonomy and phylogeny. Taxonomy refers to the classification of organisms, while phylogeny involves the study of the evolutionary history and relationships among organisms.

2. **Components of Systematics**:
- **Taxonomy**: This is the science of naming, describing, and classifying organisms into groups based on shared characteristics.
- **Phylogeny**: This is the study of the evolutionary development and diversification of a species or group of organisms.

3. **Analyzing the Options**:
- **Option 1**: "Branch of biology concerned with evolutionary relationship among organisms."
- This is correct as it encompasses both taxonomy and phylogeny.
- **Option 2**: "Branch of biology concerned with scientific classification of organisms."
- This is partially correct but does not encompass the evolutionary aspect, making it incomplete.
- **Option 3**: "Branch of biology concerned with the diversity of life."
- This does not accurately describe systematics, as it focuses more on classification and evolutionary relationships.
- **Option 4**: "Branch of biology concerned with study of multicellular organisms."
- This is incorrect as systematics applies to all organisms, not just multicellular ones.

4. **Conclusion**: The correct definition of systematics is that it is a branch of biology concerned with the evolutionary relationships among organisms, which is best represented by Option 1.