Correct Answer: Philistine

Solution : The correct choice is the third option.

The term "philistine" refers to a person who is hostile or indifferent to culture and the arts, often focusing on material or practical concerns. In the context given, someone interested in material gains and hostile to art or culture aligns with the characteristics of a philistine.

The meanings of the other options are as follows:

A perfectionist is someone who seeks perfection and high standards in their work, often paying great attention to detail.

A sage is a wise and knowledgeable person, often known for their wisdom and good judgment.

An egghead typically refers to an intellectual or highly academic person.

The word that can substitute for the given group of words "a person who is interested in material gains and is hostile to art or culture" is philistine.