Using the sentences "One thing parents should not be worried about vaccinating their kids; still, the debate rages on," and the sentence "The real culprit undermining the public's safety is a <u><em>baseless</em></u> claim that vaccinations lead to autism." Using the fact that it is baseless, we can deduce that the author thinks it is not something to worry about. This means that we can rule out B and C. Also, A is not correct because the passage rarely mentions about this, so the answer is D.
