Answer:
Step-by-step explanation:
1) C
All of the other answer choices include research such as an interview with a professional, a study, or a large-scale survey. Since this one answer choice has no factual evidence, that is a red flag.
2) D
All of the other choices are unbiased, but the nutritional supplement salesperson may be lying to sell more products! Who knows, maybe their 'immune booster drink powder' might just be sugar and food coloring that they sell for $20 per box? Any article written by a person with an agenda (which can include selling something, promoting a political organization or campaign, or advocating for a cause) are more likely to be biased.