Question

a large study of 3000 canadian children and their mothers found that the children of mothers who drank diet soda daily during pregnancy were twice as likely to be overweight at age 1 than children of mothers who avoided diet soda during pregnancy.
a newspaper article about this study had the headline \diet soda, pregnancy: mix may fuel childhood obesity.\ this headline suggests that there is a cause-and-effect relationship between diet soda consumption during pregnancy and the weight of the children 1 year after birth. however, this relationship could be explained by other variables.
what led to the wrong conclusion?
voluntary response bias
response bias
confounding
placebo effect
there was no wrong conclusion. the newspaper article got it right.

Explanation:

The question is about identifying the cause of a wrong conclusion in a study. Confounding occurs when an unmeasured variable (a confounder) affects both the independent and dependent variables, leading to a spurious association. In this case, the headline suggests a cause - effect between diet soda during pregnancy and childhood obesity, but other variables (confounders) could explain the relationship. Voluntary response bias is about self - selected samples, response bias is about inaccurate responses, and placebo effect is about the effect of belief. So the wrong conclusion is due to confounding.

Answer:

C. Confounding