A Researcher Is Interested in Examining Whether Offering Children Candy

A researcher is interested in examining whether offering children candy as an incentive to share will increase preschoolers' sharing behaviour. A group of preschoolers is brought into the laboratory to play with some interesting toys. The preschoolers are split into two groups through random assignment. Group A is told that they will get candy each time they share, and Group B is not told anything about candy or sharing. Results indicate that preschoolers in Group A share more than do preschoolers in Group B, and the researcher concludes that offering children candy for sharing caused the children in Group A to share more. Which statement BEST describes a possible limitation of this study?

A) Children in Group A may have been naturally kinder than children in Group B.
B) Causation cannot be inferred from this type of study.
C) These findings may not generalize beyond the laboratory setting.
D) There may be a third-variable problem.