It was in Salem, New Jersey in 1675. Hope this helps :)
The push factor is the second answer. Pull factor would be the opposite
Unifying, in that it creates in-group solidarity
The correct answer should be Adams' equity theory.
According to this theory, employees want to be equal at work, especially if they produce the same amount of work. So, if Bob and Tom do the same work, obviously they want to have equal paycheck as the other one, which is why Bob is unhappy because Tom's wage is higher.