In the kingdom Animalia, which of the following is not an invertebrate ?

Options

A. Platyhelminthes
B. Rotifera
C. Arthropoda
D. Amphibia

Explanation

To determine which of the options provided is not an invertebrate in the kingdom Animalia, we can follow these steps:

### Step 1: Understand the Definition of Invertebrates
Invertebrates are animals that do not possess a vertebral column (backbone). This includes a wide variety of animal phyla.

### Step 2: Analyze the Options
We have four options to consider:
- A) Platyhelminthes
- B) Rotifera
- C) Arthropoda
- D) Amphibia

### Step 3: Classify Each Option
1. **Platyhelminthes**: This phylum includes flatworms, which are invertebrates.
2. **Rotifera**: This group consists of microscopic animals known as rotifers, which are also classified as invertebrates.
3. **Arthropoda**: This is the largest phylum in the animal kingdom, including insects, arachnids, and crustaceans, all of which are invertebrates.
4. **Amphibia**: This class includes frogs, toads, and salamanders, which are vertebrates as they possess a backbone.

### Step 4: Identify the Non-Invertebrate
From the analysis, we can see that:
- Platyhelminthes, Rotifera, and Arthropoda are all invertebrates.
- Amphibia is the only group listed that contains vertebrates.

### Conclusion
Therefore, the answer to the question "In the kingdom Animalia, which of the following is not an invertebrate?" is:
**D) Amphibia**

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