In Thorndike's Puzzle Box Experiments,what Pattern of Results Would Provide

In Thorndike's puzzle box experiments,what pattern of results would provide evidence that cats were "thinking," according to Thorndike

A)  initial evidence of very quick escapes that remain unchanged 
B)  quick escapes for intelligent cats and slow escapes for unintelligent cats 
C)  initial slow escapes followed by a sharp, permanent drop in escape time once cats recognized the solution to the problem 
D)  slow escapes, then quick escapes, then slow escapes again as cats took their time to escape carefully