It is difficult to find the precise cause of any disease resulting from B-vitamin deficiencies. For example, it is known that a deficiency in all the B-vitamins causes the disease beriberi and that beriberi is always accompanied by a deficiency of vitamin B1. However, in a recent study, human volunteers did not contract beriberi despite being fed a special diet that was deficient in B1.

Which of the following if true best explains the results above?

A) Some individuals whose diets lack vitamin B1 will contract beriberi if they consume a generally unhealthful diet.
B) A deficiency in vitamin B1 is not necessary to contract beriberi.
C)Beriberi can be cured by any variety of B-vitamin supplements.
D)Beriberi is caused by deficiencies in a combination of B-vitamins.
E)Deficiencies in the B-vitamins have widely varying effects on different individuals, so that specific diseases cannot be adequately identified.

I eliminate A as option A stated that some individuals whose diets lack vitamin B1 will contract beriberi if they consume a generally unhealthful diet. Lack of vitamin B1 in diet is itself unhealthful diet. So I eliminate A.

I chose E as option E stated that deficiencies in the B vitamin have widely varying effects on different individuals,so that specific diseases cannot be adequately identified. This statement explain the result. The test result was different as person volunteer has different effect when he was fed a diet lack in vitamin B1.

OA is D. Can anyone explain me why E is eliminated.Where I am wrong?

Pls help me !!