article: National parks are large areas of public land.They give a safe home for local plants and animals.They help keep the air and water clean.They also give us the best trips.Today,there are nearly 7,000 national parks around the world.Forbes has listed 12 of the most beautiful ones in the world that will surprise you with their amazing landscapes,geographic wonders and colorful plants and animals.
  The Grand Canyon National Park of the US is one of the Seven Natural Wonders of the World.It is best known for its size and depth.It is 446 kilometers long,up to 29 kilometers wide.and 1.6 kilometers deep.The immensity of the canyon makes people think big.Every year,about 5 million people visit here.Taking a tour in the South Rim offers visitors the park's full views,while the North Rim shows beautiful wild flowers.
  If you love animals,you'll like the Serengeti National Park in Tanzania.The"Big Five"live here.They are the lion,African elephant,African leopard,black rhinocero and African buffalo.The name"Big Five"came from the five animals that were the hardest to catch.Now they are what people most want to see in the wild.If you visit the park,you should never miss the migration of over 1.5 million wildebeests and 250,000 zebras every year.This is the most famous site of the park.
question: _  kinds of animals are mentioned in the passage.
options: Five Six Seven Eight