Read the passage:
Adult sea otters spend more than a third of their day grooming their fur. This isn't for vanity; it's for survival. Unlike most sea mammals, sea otters do not have an inner layer of fat to protect them from the cold waters. These creatures rely on their dense fur instead to protect them from the often freezing temperatures. Sea otters have one of the thickest furs in all of the animal kingdom. An adult sea otter's coat can contain up to 1 billion individual hairs! These hairs form a protective, waterproof layer, which traps air and provides insulation. It is crucial that a sea otter's fur is kept clean to maintain this insulating layer between the water and their skin.
Select the best text feature to support the passage.
An animation of a sea otter eating a clam
An interactive mind map with information about different tools that sea otters use
A pie chart showing how many different animals are located in the Pacific Ocean
A video showing how sea otters clean their fur