Mobile amoeboid sponge cells digest food, transport nutrients, and can develop into other cell types. The best answer is:

Archaeocytes are amoeboid cells in sponges. They are involved in digestion, nutrient transport, skeletal element formation, and regeneration because they can differentiate into several cell types. This MCQ belongs to the Porifera topic in Animal Diversity-I and is written to test concept understanding rather than memorized wording.