Which of the following words relates closely to the concept of being suitable or applicable?

The word that relates closely to the concept of being suitable or applicable is "relevant." This term is used to describe something that is directly connected to the matter at hand and is significant in a particular context. For instance, in legal discussions, relevant evidence is critical because it informs the case at hand and helps determine outcomes based on its applicability to the situation. The focus on suitability or application directly aligns with the essence of what "relevant" conveys.

In contrast, the other options present different meanings. Prosecution pertains to the legal process of bringing a case against someone accused of a crime, which does not directly relate to the notion of suitability. Quality denotes the standard or degree of excellence of something, but it does not exclusively imply suitability or relevance in all contexts. Realized typically refers to something that has been achieved or made real, which again does not encompass the idea of being suitable or applicable. Thus, "relevant" stands out as the best choice that embodies the concept of suitability or applicability in various contexts.