12. marks (out of 30) of seven students in an examination are 4, 15., 6, 7. 5, a and b, where a (>0) is a multiple of 4 and b is a prime. what is the maximum po

12. Marks (out of 30) of seven students in an examination are 4, 15., 6, 7. 5, a and b, where a (>0) is a multiple of 4 and b is a prime. What is the maximum possible value of the range of marks (i.e., maximum mark minimum mark)? A. 25 B. 26 C. 27 D. 29