79. According to the passage, which of the following statements is correct?
(A)self-regulated practice on the Khan-College Board online learning system was less effective thanteacher-conducted practice in the classroom
(B) almost all students who practiced on the Khan-College Board online learning system made impressiveprogress
(C) students with low G.P.A. records were less likely to advance on the SAT
(D)students from low socio-economic status families advanced little on the SAT