Under the psychology of learning, regarding the nature of stimulus-response (S-R) relationships and control mechanisms among Ivan Pavlov's 'Classical Conditioning', B.F. Skinner's 'Operant Conditioning', and Edward Thorndike's 'Connectionism', which of the following analytical statements is most appropriate?

In Ivan Pavlov's classical conditioning, the stimulus precedes the response and the response is involuntary or respondent. In contrast, in B.F. Skinner's operant conditioning, the organism is active, the response is voluntary (operant), and it is controlled by its consequences (reinforcement/punishment). Thorndike emphasized the strengthening of S-R bonds through trial and error, where the law of effect plays a major role.