Final answer:
The correct answer is option a. The various excerpts demonstrate characters' interactions with the truth, ranging from denial to defense of truth in their dialogues, reflecting complex emotional and situational dynamics.
Step-by-step explanation:
The snippets provided from various literatures involve characters denying the truth or expressing doubt about situations. These passages highlight complex human emotions and interactions, especially where truth and perception are at the center of dialogue. For example, in one excerpt, the action of denying truth is portrayed when a character insists that what is believed to be true 'isn't true'.
This theme of denying truth aligns closely with the dialogue between Miss Scarlet and Professor Plum from the original question, where Miss Scarlet repeatedly denies that something is true, displaying a form of denial or refusal to accept a certain viewpoint or fact. This can be contrasted with other excerpts where characters confess, doubt, or even defend certain truths or accusations, portraying a varied range of reactions to the concept of truth.