Answer: The correct answer is B) Proximity.
Gestalt is a term in psychology that means unified as a whole.
It includes certain laws of visual perception that were developed by German psychologist in 1920.
Based on his certain principles, he deccribed how people organise visual elements into unified wholes.
According to principle of proximity, people perceive different elements as a group when they are placed together.
Thus, option B) Proximity is the right answer.