It is difficult to find the precise causes of any disease resulting fr

It is difficult to find the precise causes of any disease resulting from B-Vitamin deficiencies. For example, it was known that being deficient in all the B-vitamins was sufficient to contract the disease beriberi, and also that beriberi was always accompanied by a deficiency of vitamin B1. However, recent human volunteers on special diets designed to lack only vitamin B1, did not contract the disease.

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


(A) Individuals whose diets lack vitamin B1 will contract beriberi only if they have a generally unhealthy diet.

(B) A deficiency in vitamin B1 is not necessary to contract beriberi.

(C) Beriberi can be cured by any variety of B-vitamin supplments

(D) Berberi 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.