Seligman and Maier's Theoretical Explanation for the Inability of the Dogs

Seligman and Maier's theoretical explanation for the inability of the dogs in their Inescapable Shock condition to learn a new escape route was that they

A) had learned in the training phase that there was nothing they could do to avoid shocks.
B) had suffered brain damage from the shocks during the training phase.
C) were depressed from the training phase, which made them amotivational.
D) had learned that escape also resulted in shock so they were left with no viable behavior to avoid shock.