The correct answer is D. Blue Whale.
The blue whale is the largest animal on Earth. It is a marine mammal belonging to the baleen whale suborder Mysticeti. At 30 meters (98 ft) in length and 173 tonnes (190 short tons) or more in weight, it is the largest known animal to have ever existed. The blue whale’s long and slender body can be various shades of bluish-grey dorsally and somewhat lighter underneath.
Blue whales were abundant in nearly all the oceans of the world until the beginning of the 20th century. They were hunted almost to extinction by whalers until protected by the International Whaling Commission in 1966. The International Whaling Commission estimates that there are now between 10,000 and 25,000 blue whales worldwide.
Blue whales are filter feeders and eat mostly krill, small crustaceans that live in the water column. They have a large mouth and a series of baleen plates that hang from the roof of their mouth. The baleen plates are made of keratin, the same material that makes up human hair and nails. The blue whale uses its tongue to push krill into its mouth, and then uses its baleen plates to filter out the water.
Blue whales are social animals and live in groups of up to 100 individuals. They communicate with each other using low-frequency sounds that can travel for hundreds of kilometers.
Blue whales are an important part of the marine ecosystem. They help to keep the population of krill in check, and they are a food source for other marine animals, such as dolphins and seals. Blue whales are also a popular tourist attraction, and whale watching is a major source of income for many coastal communities.
The blue whale is a majestic creature that is an important part of the marine ecosystem. It is a symbol of the beauty and power of the natural world.