Consider the Following Statement: "Researched Conducted a Large Observational Study

Consider the following statement: "Researched conducted a large observational study and determined that children who participated in school music programs scored higher on math exams in later grades than those who did not." Suppose that upon hearing this a politician states that all children should participate in school music programs. What is wrong with the politician's statement?

A) The politician confused correlation with causation.
B) This study exhibits bias.
C) The controlled experiment was not double-blinded.
D) There was a placebo effect.