William A Sampson Compared Two Sets of Regular High Schools Against

William A. Sampson compared two sets of regular high schools against two sets of charters. He then compared each set of regular and charter schools on four achievement measures: mathematics, reading, science, and composite scores. Which of the following statements is true of the results of his comparison?

A) Charter high schools substantially outperform their regular counterparts in mathematics.
B) Regular high schools perform the same as their charter counterparts in reading.
C) Charter high schools substantially outperform their regular counterparts in composite scores.
D) Regular high schools perform the same as their charter counterparts in science.