Final answer:
An 'honest man' refers to a trustworthy person who speaks the truth and values it, contrasting with a liar, who knowingly speaks falsehoods. Therefore, the correct option is 4).
Step-by-step explanation:
In the context of the provided information, an "honest man" is best understood as a person who speaks truthfully, holding the truth in high regard. Therefore, when contrasting two types of people in the third sentence and interpreting the phrase "honest man," the closest option to its meaning would be a trustworthy person. This interpretation is reinforced by the subsequent explanations that outline a liar as someone who knows the truth yet chooses to speak against it, while an honest person speaks only what they believe to be true.
Therefore, the correct option is 4).