Suppose the proportion of sophomores at a particular college who purchased used textbooks in the past year is psand the proportion of freshmen at the college who purchased used textbooks in the past year is pf. A study

found a 98% confidence interval for ps-pfis (0.238, 0.424). Give an interpretation of this confidence interval.

A)We know that 95% of sophomores bought between 23.8% and 42.4% more used textbooks than freshmen at this college.

B)We are 98% confident that at this college the proportion of freshmen who bought used textbooks is between 23.8% and 42.4% higher than the proportion of sophomores who bought used textbooks.

C)We are 98% confident that sophomores at this college bought between 23.8% and 42.4% more used textbooks than freshmen.

D)We are 98% confident that at this college the proportion of sophomores who bought used textbooks is between 23.8% and 42.4% higher than the proportion of freshmen who bought used textbooks.