What availability of resources did Skinner manipulate in his experiment?

Skinner's experiments, particularly those involving operant conditioning, focused on how the availability of rewards influenced behavior. In his work with rats, he utilized the food supply as a primary resource to reinforce desired behaviors. When a rat completed a specific action, such as pressing a lever, it was rewarded with food. This use of food as a reinforcer played a central role in shaping the rat's behavior, as the expectation of receiving food motivated the rat to perform tasks.

The other options, while they may have some relevance to general animal behavior and learning, do not align specifically with Skinner's key manipulations in his experiments. While water could be a necessary resource, Skinner's most notable work emphasized food as the critical reward that facilitated the learning process through reinforcement. Space and social interaction, although important factors in other contexts of animal behavior, were not the primary focus of Skinner's operant conditioning research, which was primarily about the impact of rewards on behavior. Therefore, the manipulation of the food supply is what fundamentally characterized Skinner's experiments and his investigations into operant conditioning.