* 7. An exam consists of 5 questions. The post-exam score statistics are as follows: $81 \%$ of the students got the first question right; $91 \%$ of the students got the second question right; $85 \%$ of the students got the third question right; $79 \%$ of the students got the fourth question right; $74 \%$ of the students got the fifth question right.

If students who got three or more (including three) questions right are considered to have passed the exam, then the minimum pass rate for this exam is ( ).
(A) $70 \%$
(B) $74 \%$
(C) $81 \%$
(D) $73 \%$
7. A (Hint:

Assume there are 100 students taking the exam, then the total number of wrong answers is $19 + 9 + 15 + 21 + 26 = 90$ (person-questions). For a student to be不合格 (unqualified), they must get three questions wrong, and $90 \div 3 = 30$, so at most 30 students can be unqualified. On the other hand, concentrating the wrong answers on 30 students, with each getting exactly three questions wrong, is feasible. For example, 6 students get questions $1, 4, 5$ wrong; 9 students get questions $1, 2, 5$ wrong; 4 students get questions $1, 3, 4$ wrong; 11 students get questions $3, 4, 5$ wrong.