"Primitive" refers to something that is simple, basic, or undeveloped. On the other hand, "Sophisticated" implies complexity, refinement, and advanced development. Therefore, option (C) Sophisticated is the opposite or antonym of "Primitive."

In the context of the sentence, "liberal" is used to describe policies that are open to change and progress. The opposite or antonym of "liberal" in this context is "conservative," which implies a preference for maintaining existing traditions and resisting change. Therefore, option (B) conservative is the most appropriate antonym.

"Casual" refers to something relaxed, informal, or not strict. The antonym "Formal" denotes something that is official, structured, or follows established conventions. Therefore, option (C) Formal is the opposite or antonym of "Casual."

"Conceit" refers to an excessive sense of self-importance or pride, often accompanied by an overestimation of one's abilities. The antonym, "Modesty," represents a quality of being humble, unassuming, and free from excessive pride or self-assertion. Therefore, option (C) Modesty is the opposite or antonym of "Conceit."