[求助]再问L3-1-14 (blood fat- acute W)

14. The average level of fat in the blood of people suffering from acute cases of disease W is lower than the average level for the population as a whole. Nevertheless, most doctors believe that reducing blood-fat levels is an effective way of preventing acute W.
Which one of the following, if true, does most to justify this apparently paradoxical belief?
(A) The blood level of fat for patients who have been cured of W is on average the same as that for the population at large.
(B) Several of the symptoms characteristic of acute W have been produced in laboratory animals fed large doses of a synthetic fat substitute, though acute W itself has not been produced in this way.
(C) The progression from latent to acute W can occur only when the agent that causes acute W absorbs large quantities of fat from the patient's blood.
(D) The levels of fat in the blood of patients who have disease W respond abnormally slowly to changes in dietary intake of fat.
(E) High levels of fat in the blood are indicative of several diseases that are just as serious as W.

the key is c

QUOTE:my question is how the answer C explain the paradoxical belief, I just could conclude that the answer can explain the former part in the question, but how  it explains the latter part in the question(reducing blood-fat levels is an effective way of preventing acute W)?

C tell us that absoring high level of fat is a required condition to triger the disease, therefore reducing blood-fat level is an effective way to control the occurrence of the disease.

Still don't get it. Only if blood fat reduces, W occurs. But the process has nothing to do with "preventing" W. Why C??

PLEASE!