why not B
take a look at the explanation i was able to receive on other forum
The OA btw is A. What is responsible for the increased death rate for asthma over the last decade? The author mentions three potential explanations. The first two—increased and more accurate reporting and an increased urban population—cannot, according to the author, explain why asthma death rates have increased dramatically in cities with long-standing accurate records and very small urban populations. From this, the author makes the remarkable conclusion that the increase must be due to a third explanation: the use of bronchial inhalers.
This argument needs a lot of help, and fortunately, four of the five answer choices are intended to provide support, which means to help fill in the gaps. (A), however, is irrelevant: the only urban factor mentioned is increased pollution, and what relation a doubling urban population has to pollution is ambiguous at best. Mostly, however, (A) simply has no bearing on the inhaler question or the first two factors mentioned and then discredited as causes for the phenomenon. Each of the other choices, as we’ll discuss below, does have a direct bearing on these issues, whereas (A) does not.
(B) strengthens the argument by helping to rule out increased reporting as an alternative explanation for the increase in the asthma death rate. If records have been just as good for the past twenty years, then an increase in deaths over the past ten years cannot be influenced by better reporting.
(C) and (D) both suggest qualities of the bronchial inhalers that indicate that their use might play a role in increased asthma death rates. It is plausible that irritated lungs and avoiding medical treatment are causally related to death.
(E) If bronchial inhalers had been available the entire time, it would be hard to believe that they could suddenly be responsible for the recent increase in the asthma death rate. (E) thus strengthens the argument by suggesting a connection between the recent doubling of the death rates and the introduction of the proposed cause, the inhalers.