GMAT Critical Reasoning (CR) | Novice bird-watcher: I don’t know much about animal track’s

Novice bird-watcher: I don’t know much about animal track’s, but I do know that birds typically have four toes, and most birds have three toes pointing forward and one toe pointing backward. Since this track was made by an animal with four toes of which three point forward and one points backward, we can conclude it was made by some kind of bird.

The argument is flawed because it

(A) relies on the vagueness of the term “track”
(B) does not define birds as animals with four toes
(C) fails
...

---