Your company manufactures a line of facial lotions and beauty products. The company decides to extend its product line,

[correctanswer]

Your company manufactures a line of facial lotions and beauty
products. The company decides to extend its product line, adding a
new anti-wrinkle lotion. When designing the packaging of the new
lotion, your company decides to maintain the design of the existing
product line so that consumers can easily categorize the new
product as part of the existing brand. This decision is inspired by
what is known in Gestalt psychology as the principle of
________.
ground
proximity
closure
similarity
figure