A student was given a specimen to identify on the basis of the characteristics given below.
1. They are metamerically segmented.
2. They have closed circulatory system.
3. They have circular and longitudinal muscles for locomotion.
Identify the specimen

Options

A. Prawn
B. Pheretima
C. Wuchereria
D. Ctenoplana

Answer

To identify the specimen based on the given characteristics, we can follow these steps:

### Step-by-Step Solution:

1. **Analyze the First Characteristic: Metamerically Segmented**
- Metamerically segmented organisms have bodies divided into repeated segments or metameres. This characteristic is primarily found in organisms belonging to the phylum Annelida, commonly known as annelid worms.

2. **Examine the Second Characteristic: Closed Circulatory System**
- A closed circulatory system means that the blood circulates within vessels and does not leave the circulatory system. This feature is also characteristic of annelids, distinguishing them from other invertebrates that may have an open circulatory system.

3. **Consider the Third Characteristic: Circular and Longitudinal Muscles for Locomotion**
- The presence of both circular and longitudinal muscles allows for effective movement and locomotion in segmented worms. Annelids utilize these muscles to contract and expand their bodies, enabling them to move through soil or water.

4. **Identify the Specimen**
- Given that all three characteristics align with the traits of annelids, we can conclude that the specimen is an annelid worm. Among the examples provided, the correct identification is **Fertilima**, which is a common earthworm belonging to the phylum Annelida.

### Final Answer:
The specimen is **Fertilima** (an annelid worm).

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