Answer:
Equal age is not a Gestalt principle for grouping. The Gestalt principles of grouping are a set of principles in psychology that describe how humans perceive and organize visual stimuli. The principles are as follows:
Similarity: Objects that are similar in shape, color, or texture are perceived as belonging together.
Proximity: Objects that are close to each other are perceived as belonging together.
Common fate: Objects that move together or that are perceived as part of a larger movement are perceived as belonging together.
Therefore, the correct answer is equal age.