Fact 1: An aquatic animal requires great amounts of water to survive.

Fact 2: Dolphins are an aquatic mammal closely related to whales and porpoises.

Given the two facts above, answer the question "What requires great amounts of water to survive?" with the following options: 
- a tortoise
 - leeches
 - a dolphin
 - a lizard
 - a snake
 - trout
 - mussels
 - amphibians


 

   a dolphin      