Scientists hypothesize that a particular type of fat known as "P-fat" is required for the development of eyesight. Researchers were led to this hypothesis by observing that babies who are fed formulas low in P-fat tend to have worse eyesight than babies fed mother' s milk, which is high in P-fat. It has also been shown that babies that are five to six weeks premature tend to have worse eyesight than babies carried to term. Which one of the following, if true, most supports the scientists' hypothesis? ['The eyesight of a fetus develops during the last trimester of pregnancy.', "Babies generally prefer mother's milk to formulas low in P-fat.", 'Adults whose diets lack P-fat tend to have worse eyesight than those whose diets are high in P-fat.', 'A fetus typically receives high levels of P-fat from the mother during only the last four weeks of pregnancy.']