Explanation:

- Option 1: Arthropoda

- Arthropods have specialized excretory organs like Malpighian tubules.

- These function in the removal of nitrogenous wastes.

- Option 2: Porifera

- Poriferans, or sponges, lack specialized excretory organs.

- They rely on diffusion for waste removal.

- Option 3: Mollusca

- Mollusks utilize nephridia for excretion.

- The process is more complex than simple diffusion.

- Option 4: Hemichordata

- Hemichordates have a proboscis gland, also known as the glomerulus.

- It plays a role in the excretion of waste products.

- Correct Answer: Hemichordata