Answer:
Animal 1
Step-by-step explanation:
By the definition we know:

From the given data table we calculate the speed of each animal at the given distance points.

Animal 1:
after 25 meters:


after 50 meters:


enough to prove that there exists acceleration because of change in speed with time.
Animal 2:
after 25 meters:


after 50 meters:


after 75 meters:


has constant speed, hence no acceleration.
Animal 3:
after 25 meters:


after 50 meters:


after 75 meters:


has constant speed, hence no acceleration.
Animal 4:
after 25 meters:


after 50 meters:


after 75 meters:


has constant speed, hence no acceleration.