Final answer:
A hug for doing something right is an example of an informal positive sanction, rewarding the child for conforming to norms and representing a type of social control to encourage desirable behaviors.
Step-by-step explanation:
The correct answer to the student's question is A) Informal positive sanction. When a child is given a hug for doing something right, it serves as a reward for conforming to norms and it arises out of informal social interaction which makes it an informal action. This type of sanction is positive because it is expressing approval and rewarding the child for good behavior, unlike a negative sanction which would involve some form of disapproval or punishment for undesirable behavior. These sanctions are part of social control mechanisms that encourage conformity to societal norms and values. Formal positive sanctions, for example, might involve official recognition such as certificates or trophies, whereas an informal positive sanction such as a hug is more personal and spontaneous.