Final answer:
One should choose a credible speaker, especially when trying to convey factual information or when seeking to persuade an audience that may be skeptical or possess a certain level of expertise.
Step-by-step explanation:
Choosing a Credible Speaker
When deciding on a speaker, one should choose a credible speaker when trying to convince the crowd of factual information. Credibility is a crucial feature of a persuasive message because credible speakers, who are perceived as having expertise and being trustworthy, have a greater influence than less credible sources.
According to Hovland & Weiss (1951), features of the source, such as credibility, significantly affect persuasion. This underpins why reputable individuals are often utilized in advertising. These principles also relate to informational social influence, particularly when individuals need to make judgements based on complex information or when the group is knowledgeable on the topic, thereby making arguments more persuasive when presented by someone with the right expertise.
Informational social influence is more likely when the answer to a question or situation is unclear and when members of a group have expertise (option d, both b and c). Thus, selecting a speaker with credibility is indeed important under these conditions, as they are more likely to persuade and change the attitudes or behavior of an audience, especially when the audience may not initially agree with the message.
For the central route to persuasion to be effective, the audience must be analytical and motivated, and this often requires presenting a logical argument supported by evidence from a credible source. Hence, when an audience is skeptical or the topic requires detailed understanding, choosing a credible speaker is essential.