Which of the following scenarios should be analyzed as paired data?
a) Spouses are asked about the number of hours of sleep they get each night. We want to see if husbands get more sleep than wives.
b) 50 insomnia patients are given a placebo and 50 are given a mild sedative. Which subjects sleep more hours?
c) A group of college freshmen and a group of sophomores are asked about the quality of the university cafeteria. Do students' opinions change during their time at school?