The correct option is
C a - r, b - s, c - p, d - q
A. Pseudopodia, also known as false feet, are the projections of the plasma membrane in some protozoans such as Amoeba. These help the organism to move and engulf food particles.
B. Parapodia are the locomotory organs in Annelids.
C. Muscular foot is present in Molluscs and used for anchorage and locomotion.
D. Fins are present in fishes and aid them in swimming. Paired fins are present in Chondrichthyes, a class of Cartilaginous fishes.
Hence, the correct match is a - r, b - s, c - p, d - q
So, the correct answer is 'a - r, b - s, c - p, d - q'.