Question

{"given":"A list of organisms: snail, cockroach, and cuttlefish.","key_observation":"Cephalopods are the only class of molluscs that possess a closed circulatory system, whereas most other molluscs and arthropods have an open circulatory system.","formula_steps":[],"option_analysis":[{"label":"(A)","text":"Snail","verdict":"incorrect","explanation":"Snails belong to the class Gastropoda of the phylum Mollusca, which typically have an open circulatory system."},{"label":"(B)","text":"Cockroach","verdict":"incorrect","explanation":"Cockroaches belong to the phylum Arthropoda, which are characterized by having an open circulatory system where blood flows freely in the hemocoel."},{"label":"(C)","text":"Cuttlefish","verdict":"correct","explanation":"Cuttlefish (e.g., Sepia) belong to the class Cephalopoda of the phylum Mollusca. Cephalopods are unique among molluscs as they possess a closed circulatory system. They have two branchial hearts (gill hearts) that move blood through the capillaries of the gills, and a single systemic heart that pumps the oxygenated blood through the rest of the body."},{"label":"(D)","text":"All of these","verdict":"incorrect","explanation":"Since snails and cockroaches have open circulatory systems, this option is incorrect."}],"answer":"(C)"}