Answer:
b) single loop
Explanation:
In fishes, deoxygenated blood is carried to the heart which in turn pumps it to the gills for exchange of gases. Oxygenated blood is delivered from gills to the body parts.
As per given information, fishes exhibit a single loop circulatory system. If the blood passed through the heart only once during one loop of circulation, the system is said to be single loop circulation.
