Final answer:
The fundamental motivation behind the arousal/cost-reward model is incentive-based reinforcement, focusing on the balance of benefits and costs in behavior motivation.
Step-by-step explanation:
The fundamental motivation underlying the arousal/cost-reward model is a) Incentive-based reinforcement. This model posits that the motivation for a behavior comes from the balance of potential rewards and costs associated with the action. The idea is that individuals will engage in behaviors that provide the most incentive while minimizing costs. This approach aligns with concepts of operant conditioning, a form of learning where behaviors are influenced by consequences, specifically reinforcements (both positive and negative) that increase the likelihood of a response, as proposed by B. F. Skinner.