Answer:
primary and secondary reinforcers
Explanation:
A reinforcer is something which increases the probability of a particular action or response. Positive reinforcements add something to change behaviour, while negative reinforcements take away something. Primary reinforcers are biological. Secondary reinforcement relates to a situation in which a stimulus strengthens a behavior after historically identified with a primary reinforcer or stimulus that satisfies basic survival instincts.
Whilst the primary reinforcing agents are biological in nature, secondary reinforcing agents need affiliation with these intrinsic reinforcing agents until they can react.
Water here is the primary reinforcer, while petting is a secondary reinforcer.