[求助]一道补充材料的逻辑

Blood banks will shortly start to screen all donors for NANB hepatitis. Although the new screening tests are estimated to disqualify up to 5 percent of all prospective blood donors, they will still miss two-thirds of donors carrying NANB hepatitis. Therefore, about 10 percent of actual donors will still supply NANB-contaminated blood.

20. Which of the following inferences about the conse-quences of instituting the new tests is best supported by the passage above?

(A) The incidence of new cases of NANB hepatitis is likely to go up by 10 percent.
(B) Donations made by patients specifically for their own use are likely to become less frequent.
(C) The demand for blood from blood banks is likely to fluctuate more strongly.
(D) The blood supplies available from blood banks are likely to go down.
(E) The number of prospective first-time donors is likely to go up by 5 percent.

答案是d。不明白血液供给为什么会减少，是因为disqualify up to 5% 了么？我选的是b.
谢谢大家：）

楼上的xdjm没说为什么选B，B的意思是：病人以自己使用为目的而进行的献血（应该不是真正意义上的献血了）可能会减少。题干完全没有提这个呀。

rice3434 gg说“不明白血液供给为什么会减少，是因为disqualify up to 5% 了么？”我觉得是的。

选b是因为觉得 别的“太”不对了。原因有一点是因为不能检测出来全部肝炎，所以就让整个血库都有病毒了，所以那些想要自己用的人就简少了。现在看来，即使不使用新的方法也不能全部检测出来。所以这跟新方法没什么关系了

呵呵 感觉像自己逗自己玩呢 我都快哭了……