Which of the following animals is the most complex? Base your decision on body plan, structures used to carry out various functions, and structures used to respond to the environment. flatworms sponges hydras sea urchins
The most complex animal is pretty much all of them..if i had to pick 1..it would have to be the black rhino..there aren't much in the world and also, they're more complex than white rhinos, as far as I know.