In Metzgar's Experiments on Learning in White-Footed Mice,the Screech Owls

In Metzgar's experiments on learning in white-footed mice,the screech owls

A) allowed observers to examine the effects of fear in the mice.
B) provided a warning system for the mice.
C) allowed observers to see which mice would hide from the predator.
D) allowed observers to see which mice would run faster in response.
E) served as a control.