We can now dismiss the widely held suspicion that sugar consumption

We can now dismiss the widely held suspicion that sugar consumption often exacerbates hyperactivity in children with attention deficit disorder. A scientific study of the effects of three common sugars—sucrose, fructose, and glucose—on children who have attention deficit disorder, with experimental groups each receiving a type of sugar in their diets and a control group receiving a sugar substitute instead of sugar, showed no statistically significant difference between the groups in thinking or behavior.
Which one of the following, if true, would most weaken the argument above?
(A) Only one of the three types of sugar used in the study was ever widely suspected of exacerbating hyperactivity.
(B) The consumption of sugar actually has a calming effect on some children.
(C) The consumption of some sugar substitutes exacerbates the symptoms of hyperactivity.
(D) The study included some observations of each group in contexts that generally tend to make children excited and active.
(E) Some children believe that they can tell the difference between the taste of sugar and that of sugar substitutes.