The second answer is true, lung cancer is the leading cause of cancer deaths.
The answer is B because when the product is still being used after it's expiration date, it has higher chances of having mold or spoiling. That's why you would always want the product with the latest expiration date, so that the product won't expire so early. In which could mean that that type of product is the freshest.
B is the best answer since public health policies reduce probabilities of diseases. It is not an obligation to provide vaccination since these are costly but these will be made readily available as much as needed and can be provided.