"Achoo! Everyone suffers from the miserable symptoms of the common cold. Lots of boxes of tissues later, you wish someone would fix you up as good as new. Well, folks. Guess what? Your wishes are about to come true. Our lab will win next year's Nobel Prize in Medicine for the discovery that all you really need is some hot tea and sympathy. Grandma was right, after all." Why might you question the reliability of the author's claim that the lab will win a Nobel Prize in Medicine?

There isn't actually a reason to believe this

Explanation:

Viewers might wonder, "how can hot tea cure us??" "where is the reason?" "why should we believe this!?"

D. Josie will lead the discussion it is about a topic she knows well.

Explanation:

A fused sentence also exemplifies a run-on sentence that lacks a proper conjunction or punctuation mark(comma or semicolon) where the two independent clauses run together. These sentences are generally treated as errors that can be rectified by adding an appropriate punctuation mark or a subordinate or coordinate conjunction.

Thus, the sentence that exemplifies this claim would be the last option "Josie will lead the discussion it is about a topic she knows well" which would read as following after fixing this error:

"Josie will lead the discussion as it is about a topic that she knows well".