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 than teacher-conducted practice in the classroom (B) almost all students who practiced on the Khan-College Board online learning system made impressive progress (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