Find the related word.

Pi : Circle :: Phi : ?

The logic followed here is:

Logic: The first term is a mathematical constant or ratio associated with the second term.

Here,

Pi : Circle → Pi (π) is the ratio of a circle's circumference to its diameter, a fundamental constant associated with a Circle.

Similarly,

Phi : ?

Phi (ϕ) is another mathematical constant, known as the Golden Ratio. It appears in various natural and geometric contexts, often associated with aesthetic proportions.

Hence, the correct answer is "Option 2".