Answer:
CONVENTIONAL.
Explanation:
Lawrence Kohlberg defined three levels of moral development: preconventional, conventional, and postconventional. Each level has two distinct stages.
During the preconventional level, a child’s sense of morality is externally controlled. Children accept and believe the rules of authority figures, such as their parents and teachers.
During the conventional level, an individual’s sense of morality is tied to personal and societal relationships. The individual strives to support rules that are set forth by others such as parents, peers, and others in order to win their approval or to maintain social order.
During the post-conventional level (also known as the principled level), individuals may disobey rules inconsistent with their own principles.
Since Susan knows it is wrong to cheat but decides not to report to the teacher because she doesn't wants to called a snitch by other kids, this means she is trying to win their approval and maintain the social order between them. Therefore, this is an example of Lawrence Kohlberg's CONVENTIONAL stage of moral development.