Statement (S). Arthropoda are the most successful of all known animal groups
Reason (R). Arthropoda exhibits the greatest adaptive radiations and have adapted to diverse habitats.

Options

A. Both S and R are true and R explains S.
B. Both S and R are true but R cannot explain S.
C. Only S is correct R is wrong.
D. Both S and R are wrong.

Answer

### Step-by-Step Solution

1. **Understanding the Statement (S)**: The statement claims that "Arthropoda are the most successful of all known animal groups." This suggests that arthropods have a significant presence and diversity compared to other animal phyla.

2. **Understanding the Reason (R)**: The reason provided states that "Arthropoda exhibits the greatest adaptive radiations and have adapted to diverse habitats." This indicates that the success of arthropods is linked to their ability to adapt to various environments.

3. **Analyzing the Success of Arthropoda**:
- Arthropoda is the largest phylum in the animal kingdom, comprising about two-thirds of all known species, primarily due to insects.
- Their success can be attributed to their evolutionary adaptations, which allow them to thrive in numerous habitats, from terrestrial to aquatic environments.

4. **Identifying Key Adaptations**:
- One of the main adaptations that contribute to their success is the presence of a chitinous exoskeleton. This exoskeleton provides structural support and protection, enabling arthropods to survive in various conditions.
- The chitinous exoskeleton allows for both terrestrial and aquatic adaptations, making them versatile in different environments.

5. **Linking Statement and Reason**:
- Both the statement and the reason are true. The reason (R) explains the statement (S) because the adaptive radiations and ability to occupy diverse habitats are key factors that contribute to the success of arthropods.

6. **Conclusion**: Since both the statement and the reason are true, and the reason explains the statement, we conclude that the correct answer is that both S and R are true, and R explains S.

### Final Answer
Both the statement (S) and the reason (R) are true, and R explains S.

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