The phylum arthropoda is named so because of presence of

Options

A. Jointed appendages
B. segmentation
C. chitinous exoskeleton
D. Organ-system level of organisation

Explanation

### Step-by-Step Solution:

1. **Understanding the Phylum Name**: The name "Arthropoda" is derived from Greek words. "Arthro" means joint and "poda" means foot or leg. This indicates that the defining characteristic of this phylum is related to its appendages.

2. **Identifying Key Characteristics**: The phylum Arthropoda is characterized by:
- Jointed appendages (legs, antennae, etc.)
- Segmentation of the body into distinct regions (head, thorax, abdomen)
- A chitinous exoskeleton that provides protection and support
- An organ system level of organization, which includes specialized systems for respiration, circulation, and nervous functions.

3. **Focusing on Jointed Appendages**: Among these characteristics, the most significant feature that distinguishes Arthropoda from other phyla is the presence of jointed appendages. This feature allows for greater mobility and flexibility.

4. **Conclusion**: Therefore, the phylum Arthropoda is named so primarily because of the presence of jointed appendages.

### Final Answer:
The phylum Arthropoda is named so because of the presence of jointed appendages.

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