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

Fact 2: Water remains in the current of the river.

Given the two facts above, answer the question "What helps an animal move through a river better?" with the following options: 
- salinity
 - scales
 - long snout
 - long tail
 - contracting
 - stamina
 - long fur
 - four limbs


 

    long tail     