A Study Is Commissioned to Determine Whether Piglets Gain Body

Multiple Choice

A study is commissioned to determine whether piglets gain body mass more rapidly when a certain hormone is introduced into their feed. In January, a random sample of 40 10-week-old piglets receives a diet that includes the hormone. Sixteen weeks later, the average weight increase is determined. A similar experiment is conducted the following June with a random sample of 36 piglets, except the hormone is removed from the diet. ​
Which of the following do you think represents the most serious flaw in this study?
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A) the presence of a confounding variable
B) the presence of a sampling bias
C) an absence of experimental control
D) the presence of a measurement bias
E) inadequate information regarding dietary needs of piglets