Final answer:
Chris can bolster his credibility through discussing shared challenges, detailing his relevant background in social media marketing, and speaking with passion and sincerity.
Step-by-step explanation:
Chris can enhance his credibility when giving a speech on social media marketing in several ways. Firstly, he should highlight the marketing challenges that he and the audience share, this makes his content relatable and relevant. Secondly, Chris should describe his background and experience in social media marketing, providing concrete evidence of his expertise in the field. Lastly, speaking with genuine passion and from the heart can convey his commitment and personal investment in the topic, making his speech more engaging and convincing