Final answer:
The two main factors that make a source credible are the credibility of the speaker or author and the physical attractiveness of the speaker.
Step-by-step explanation:
Research suggests that there are two main factors that make a source credible: the credibility of the speaker or author, and the physical attractiveness of the speaker. Credible speakers are those who have expertise on the topic and are deemed trustworthy by the audience. Additionally, more attractive speakers are generally more persuasive. These factors contribute to the overall credibility of a source.
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