During these days where almost all things become instant, the drawback that is traded especially in the social realm of the people is the lack of copresence during meetings. Instead of spending time talking about problems and whereabouts, attentions are diverted to social media sites instead.
I assume that the question is not necessarily directed at people, but that it can refer to the training of animals, such as dogs.
The most effective kind of reward is food and praise - and this is in fact the kind of reward most commonly used in dog training.
The answer to this is C... Hope this helps :)
The answer is: The spotlight effect
The spotlight effect usually caused by low-self esteem. People who experience a spotlight effect will perceive every small movement made by other people as something directed to praise or insult them. It is believed that the usage of social media increases the number of people who experience this effect.