Skinner's Invention of the Operant Chamber and Cumulative Recorder Marked

Multiple Choice

Skinner's invention of the operant chamber and cumulative recorder marked an advance over Thorndike's apparatus in that

A) subjects could now live in the experimental situation.
B) the subjects did not have to be handled too often; they could also emit responses freely.
C) the speed of escaping the puzzle box could be more accurately recorded.
D) the response rate could be measured and figured into a formula that calculates statistical significance.
E) researchers could now have complete control of the operant response.