Answer:
A. Big drugstores benefit from the spread of the flu virus
Explanation:
According to the given article, "What a
Bad Flu Season Could Cost the US Economy", the implicit message that can most clearly be inferred from the article is that big drugstores benefit from the spread of the flu virus.
This is because, vaccine development is a difficult and expensive process which makes the big drugstores very wealthy at the expense of other people.