86. If you were to use the scientific method to determine if eating oat bran decreases people’s chance of getting cancer, which of the following studies would be best at answering the hypothesis....

86.  If you were to use the scientific method to determine if eating oat bran decreases people’s chance
of getting cancer, which of the following studies would be best at answering the hypothesis.
Assume it is possible to do each of the proposed studies.

a. Survey 10,000 people who had cancer and 10,000 people who have not had cancer and
see if one group ate more oat bran than the other.

b. Select 10,000 people and ask them about how much oat bran they eat each week.
Follow up on them over many years and see if the people who eat more oat bran are less
likely to get cancer.

c. Take a group of 500 people and randomly place 250 in each of two groups. Give one
group two servings of oat bran every day for 20 years, and the other group two servings
of some other food and see which group has more cancer cases in those 20 years.

d. Find which ethnic groups eat the most oat bran and then compare cancer rates between
those groups (since you would have a very large sample size).