In the Classic Experiment by Dr

In the classic experiment by Dr. Martin Seligman, how did the dogs act in the final phase of the study when they were all able to escape? This question is based on the Faces Interactive Dysthymic Disorder Module

A) Dogs that encountered a barrier earlier were the fastest to escape
B) Dogs that encountered a barrier earlier made no effort to escape
C) Dogs that did not encounter a barrier earlier made no effort to escape
D) All of the dogs made an equal effort to escape