Which of the following is not the feature of Phylum Mollusca?

Options

A. Muscular foot
B. Soft unsegmented body
C. Calcareous shell
D. Jointed legs

Explanation

To determine which of the following is not a feature of Phylum Mollusca, we will analyze each option provided:

1. **Muscular foot**: This is a characteristic feature of mollusks. The muscular foot is used for locomotion and can also be adapted for other functions like capturing prey.

2. **Soft, unsegmented body**: Mollusks have a soft body that is not segmented. This is another defining characteristic of the phylum.

3. **Calcareous shell**: Many mollusks possess a shell made of calcium carbonate, which serves as protection. This is also a typical feature of mollusks.

4. **Jointed legs**: This feature is not associated with mollusks. Jointed legs are characteristic of the phylum Arthropoda, which includes insects, arachnids, and crustaceans.

Based on the analysis above, the feature that is not characteristic of Phylum Mollusca is **jointed legs**.

### Final Answer:
The feature that is not a characteristic of Phylum Mollusca is **jointed legs**.