Q: 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 they received in the three terminal examinations, in which the pass-marks were 50%. Examiners are instructed to follow the following criteria : 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 1 and 2, 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 of the above criteria, which of the following would definitely not be permissible?