A child is praised for using his fork instead of his fingers to eat some spaghetti. This is an example of

The correct answer is B. positive.

This situation exemplifies positive reinforcement because the child’s behavior of using a fork is being encouraged through praise. Positive reinforcement involves adding a pleasant stimulus (praise, in this case) following a desired behavior (using a fork), which increases the likelihood of that behavior being repeated in the future. If you have more questions or need further assistance, feel free to ask!