A recent article reported on a new loyalty program by fast-food chain Zaxby's and stated: "Zaxby's most loyal customers...will receive a free Big Zax Snak Meal with every new download or update of the existing app." Based only on this information, which learning theory is influencing Zaxby's marketing actions? a. Observational learning b. Instrumental conditioning c. Cognitive learning theory d. Classical conditioning e. Rewards learning theory