The question below has some statement / argument / report / passage, followed by a few alternative answer choices marked A, B, C and D, of which only one would be the best possible answer. Read the passage / statement / argument carefully and choose the best possible answer from the alternatives given. In an examination system of an institution, 100 students have been graded (from A − D in descending order) on the basis of the marks in the three terminal examinations. The pass-marks were 50%. Examiners are instructed to follow the following criteria : Which of the following statements is/are correct ? — 1. All students who scored between 90% and 100% in any two examinations could receive an A. 2. Students who came in the top overall were to be awarded an A. 3. Notwithstanding I and II, if any student failed a paper, the highest he or she could get was a B. 4. The top 20 students in the whole year, when the overall examination percentages were averaged, could receive an A. On the basis