Answer:
B. Operant conditioning
Explanation:
In psychology, the term operant conditioning refers to a form of learning by reinforcements and punishments.
According to this, a reinforcement is an stimulus that increases the probability that a certain behavior takes place again in a future, so, <u>when the individual is presented with this stimulus, the behavior will be more likely repeated in the future and it will happen more often.</u>
In this example a child smiles and gains attention, <u>the reinforcement would be the gaining of attention, which would be the stimulus that is making the child to begin to smile more often</u>. Gaining attention is something desirable and pleasant for the child so it's a reinforcement for the conduct of smiling.
Therefore this is an example of b. operant conditioning.
