Final answer:
The student's belief that cheating is wrong because it is important to follow rules indicates that they are at the B) conventional stage of Kohlberg's moral development.
Step-by-step explanation:
Lawrence Kohlberg's theory of moral development categorizes the student's argument that "Cheating is wrong; it is important to follow rules" as an example of the conventional level of moral reasoning. In this stage, individuals make moral decisions per societal rules and norms, emphasizing obeying laws and fulfilling social roles.
The reliance on rules and conformity to societal expectations signifies that the individual is considering what is deemed right by society, as opposed to the self-centered reasoning characteristic of the pre-conventional stage or the abstract principled reasoning of the post-conventional stage.