A Columbia University Study Linked Soda Consumption to Behavior Problems

Multiple Choice

A Columbia University study linked soda consumption to behavior problems in children.Researchers examined data from a previous study that followed 2929 mother-child pairs.One survey asked about behaviors of the child and also about soda consumption.They found that the more soda the kids drank, the more behavior problems they had.What aspect of a well-designed experiment is absent from this study?

A) a control group
B) randomization
C) blinding
D) a placebo
E) all of these