A) Correct option is (B)B) Explanation is correct option (B)In sponges, there is a cellular level of organisation. Different cells have different functions as:Pinacocytes are the skin cells of sponges and line the exterior of the body wall. They are slightly contractile and help sponges to change shape. There is a jelly-like layer under pinacocytes, called mesohyl. Mesenchyme cells are amoeboid and move about in the mesohyl. They are specialised in reproduction, transporting and storing food, secreting skeletal elements. beneath mesenchyme are choanocytes or collar cells. These are flagellated cells with a ring of microvilli surrounding flagella. It helps in filtering particles.