Fact 1: Along tail can be used to move through water by an animal.

Fact 2: Tail fin is long and swept.

Given the two facts above, answer the question "what sweep through water by animals?" with the following options: 
- floaties
 - water marks
 - tail fins
 - clams
 - squids
 - water shoes
 - salmon
 - Nematoda


 

   tail fins      