The BEST answer choice that explains how the author refines the meaning of the term "Samurai" over the course of the article is (A) by expanding on the concept of the heroic warrior with details about what made samurai unique.
Throughout the article, the author provides details and examples that highlight the unique characteristics and qualities of samurai, such as their strict code of honor, loyalty to their lords, skill in combat, and artistic pursuits. The author expands on the concept of the heroic warrior by explaining what specifically made samurai different from other warriors and soldiers of their time. By doing so, the author refines the meaning of the term "Samurai" and helps the reader better understand the historical and cultural context in which these warriors lived and operated.