【正确答案】 C

【答案解析】The sperm whale is the largest toothed whale. An adult male grows to be about 50-60 feet long and a female is smaller, about 33-40 feet long. It has no back fin but has a small hump two-thirds of the way down its back. There are also some ridges between the hump and the tail flukes. The north right whale is a baleen whale with bow-shaped lower jaw and a head that is up to one-quarter of the body length. Northern right whale females grow to be about 50 feet long, while males are about 49 feet long. They have large flippers but no back fin. The minke whale is the smallest baleen whale with about 25-30 feet long, just one fourth of the blue whale. They are the most abundant baleen whale. They have a characteristic white band on each flipper, contrasting with their very dark gray top color.