Final answer:
(B) Monkfish is the type of lean fish that is low in fat among the given options. Salmon, which is also a ray-finned fish, has higher fat content and is not considered lean.
Step-by-step explanation:
The type of lean fish that is low in fat from the given options is monkfish (B). Unlike monkfish, salmon, mackerel, and pompano are known to have higher fat content. Monkfish belongs to the ray-finned fishes, which have bony endoskeletons and are characterized by their fins, which are webs of skin supported by bony spines called rays.
Salmon, which is also a ray-finned fish, typically has more fat, making it not a lean fish. Therefore, monkfish is considered a lean fish and is suitable for diets that aim to lower fat intake.