Final answer:
The word 'aspersion' refers to both a defamatory expression and slander, related to statements that harm one's reputation.
Step-by-step explanation:
The meaning of the word 'aspersion' is most closely associated with both a defamatory expression and slander. Hence, the correct answer would be option 3) Both a and b. An aspersion refers to an attack on the reputation or integrity of someone or something. It implies a negative reflection or insinuation about a person, which can be damaging to their character or reputation. While the term itself does not always exclusively refer to false statements, it is typically used in the context of statements that can harm one's reputation, which aligns with the concepts of slander and defamation.