Final answer:
The term 'squealer' closest aligns with the option 'C. Whistleblower,' indicating a person who exposes wrongdoing within an organization.
Step-by-step explanation:
The term “squealer” does not have a positive connotation and typically refers to someone who informs on others, often in a negative or betraying manner. However, in the context of the provided options, the term closest in meaning to “squealer” from the choices is C. Whistleblower, which describes a person who exposes wrongdoing within an organization in the hope of stopping it. The other options—A. Silent observer, B. Truth-teller, and D. Mute spectator—do not align with the typical implications of being a “squealer.” Option A and D suggest a person who watches events without participating or revealing information, while option B implies someone who is dedicated to sharing the truth, without the negative associations of a “squealer.”