What does "ignorant" most closely mean in the sentence: "He was ignorant of the proper procedures."?

In the context of the sentence, "ignorant" refers to a lack of knowledge or awareness about proper procedures. The term implies that the individual does not know or is not informed about something specific—in this case, the correct procedures. "Unaware" captures this meaning accurately, as it indicates that the person does not have the pertinent information or knowledge at that moment.

The other choices revolve around the perception of knowledge but do not fit the context as precisely. "Conscious" suggests an active awareness rather than absence of knowledge. "Uncertain" implies doubt or indecision rather than a lack of knowledge. "Cognizant" indicates an awareness or understanding of something, which is the opposite of being ignorant. Thus, "unaware" is the best choice, as it directly aligns with the meaning of lacking knowledge in this scenario.