To What Sort of Treatment Were the Dogs in Seligman's

To what sort of treatment were the dogs in Seligman's experiment on learned helplessness exposed?

A) They were exposed to electrical shocks with no chance to escape.
B) They were deprived of water until they learned to bark on command.
C) They were deprived of food until they engaged in complicated physical acts.
D) They were suspended by harnesses and unable to get back to the ground until they learned to turn themselves around in the air by kicking their paws in a sequential fashion.