Unsegmented body is found in

Explanation:

• Platyhelminthes (Flatworms): These are soft-bodied, unsegmented invertebrates with a flattened shape. They lack specialized circulatory and respiratory systems, relying on diffusion for gas exchange.
• Roundworms (Nematodes): Also known as nematodes, these are cylindrical, unsegmented worms with a complete digestive system. They possess a pseudocoelom and are covered by a tough cuticle.

In contrast, other groups mentioned in the options have segmented bodies:

• Annelids: Segmented worms like earthworms, characterized by a series of repeating segments.
• Arthropods: Invertebrates with segmented bodies, exoskeletons, and jointed appendages, including insects, arachnids, and crustaceans.
• Pisces (Fish): Vertebrates with segmented muscles and vertebrae.

Therefore, among the options provided, Platyhelminthes and Roundworms are the phyla with unsegmented bodies. The correct answer is d) Platyhelminthes, Roundworms.