Platyhelminthes are best described as

Explanation: Platyhelminthes, commonly known as flatworms, are triploblastic because they have three germ layers (ectoderm, mesoderm, and endoderm). They are acoelomate, meaning they lack a body cavity between the gut and the outer body wall. This makes option 1 the correct description.

Why the other options are incorrect:

• Option 2 (Diploblastic, acoelomate): Platyhelminthes are triploblastic, not diploblastic. Diploblastic organisms have only two germ layers (ectoderm and endoderm), which is not the case for flatworms.
• Option 3 (Triploblastic, coelomates): Platyhelminthes are acoelomate, meaning they lack a true body cavity (coelom), so this option is incorrect.
• Option 4 (Triploblastic, pseudocoelomates): Platyhelminthes do not have a pseudocoelom (a body cavity that is not fully lined by mesoderm), so this option is also incorrect.

Final Answer

Platyhelminthes are best described as: Flatworms, triploblastic, acoelomate animals