Please read the following passage and then answer questions 46-47.
        Ever since Nobel prize-winner Linus Pauling first advocated vitamin C as a common-cold warweapon more than 20 years ago, researchers have been busy trying to verify that claim. But so far,they've found little proof that vitamin C prevents colds. In fact, there are more studies that say itdoesn't. But there is evidence that it can keep coughing and sneezing to a minimum, and that lowlevels of vitamin C in the body may be related to bronchitis.
【題組】46. From the passage, we can learn that Dr. Pauling's view as regards vitamin C________ .
(A) has greatly improved the treatment of bronchitis
(B) has caused a revolution in medical studies
(C) aroused very little interest among medical exports
(D) was based on the results of years of research
(E) has not been verified scientifically