If you name a cow and regularly mention the cow's name when you are talking to it, will the cow yield more milk than a cow who is not talked to by name? To investigate this, researchers surveyed 375 dairy farmers in the United Kingdom. They asked each farmer if they regularly refer to their cows by name. They also asked each farmer how much milk their cows typically produce each year. The researchers found that cows who were regularly referred to by name produced an average of 500 more pints per year of milk than cows who were not regularly referred to by name. Based on this information, which of the following statements is correct?

A. The explanatory variable is the amount of milk produced by the cows.

B. The individuals are the farmers.

C. This study is an example of an experiment.

D. The response variable is the name of the cow.

E. None of the above answer options are correct statements.