Naiads are

Options

A. Nymphs of Locust
B. Nymphs of Grasshopper
C. Nymphs of Dragonfly
D. All the above.

Answer

**Step-by-Step Solution:**

1. **Understanding the Term "Naiads":** Naiads refer to the immature aquatic forms of certain insects, particularly those belonging to the order Odonata (which includes dragonflies and damselflies) and Ephemeroptera (mayflies).

2. **Identifying the Options:** The question provides several options:
- Nymph of locust
- Nymph of grasshopper
- Nymph of dragonfly
- All of the above

3. **Analyzing Each Option:**
- **Nymph of locust:** This is incorrect because locusts do not have an aquatic nymph stage; they undergo incomplete metamorphosis.
- **Nymph of grasshopper:** This is also incorrect for the same reason as locusts; grasshoppers also do not have a nymph stage that is aquatic.
- **Nymph of dragonfly:** This is correct because dragonflies have a nymph stage (naiad) that is aquatic and is distinct from the adult form.

4. **Conclusion:** The correct answer is the nymph of dragonfly, which is specifically referred to as a naiad.

5. **Final Answer:** The correct answer is option 3: nymph of dragonfly.

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