Orchids, ferns, fruit trees, parrots, and frogs are just some of the thousands of species that can be found in australia’s ecosystem. a. desert b. grassland c. marine d. rainforest

I would say the answer is - D. rain forest

Hope that helps :P

D. Rain-forest, because all those things you listed cannot be found in a dessert or underwater. And grassland doesn't have enough places for a frog to hide and enough moisture for ferns to grow. 

They looked like staggered steps mark me brainliest