Step-by-step solution
Molluscs primarily use gills for respiration, which is known as branchial respiration. Thus, A matches II. Reptiles rely exclusively on lungs for gas exchange, which is termed pulmonary respiration. Thus, B matches I. Adult amphibians, such as frogs, can respire through both their lungs and their moist skin, utilizing pulmonary and cutaneous respiration. Thus, C matches IV. Amoeba is a unicellular organism that exchanges gases directly across its cell membrane via simple diffusion, which corresponds to cellular respiration. Thus, D matches III. The correct matching is A-II, B-I, C-IV, D-III. Answer: A-II, B-I, C-IV, D-III