Researchers conducted a study to investigate the effects of soft drink consumption on fat stored in muscle tissue. from a sample of 80 adult volunteers, 40 were randomly assigned to consume one liter of a soft drink each day. the remaining 40 were asked to drink one liter of water each day and not to consume any soft drinks. at the end of six months, the amount of fat stored in each person’s muscle tissue was recorded. the people in the group who drank the soft drink had, on average, a higher percentage of fat stored in the tissue than the people who drank only water.

which of the following is the most appropriate conclusion?
a. there is evidence that consuming soft drinks causes more fat storage in muscle tissue than drinking only water, and the conclusion can be generalized to all adults.
b. there is evidence that consuming soft drinks causes more fat storage in muscle tissue than drinking only water, and the conclusion can be generalized to adults similar to those in the study.
c. although cause-and-effect cannot be established, there is an association between consuming soft drinks and fat storage in muscle tissue for the population of all adults who consume soft drinks.
d. there is evidence that consuming soft drinks causes more fat storage in muscle tissue than drinking only water, and the conclusion can be generalized to all people who consume soft drinks.
e. although cause-and-effect cannot be established, there is an association between consuming soft drinks and fat storage in muscle tissue for the population of all adults.