The histogram shows the marks scored by 40 students in a test with maximum 30 marks.

What is the ratio of the number of students who scored marks in the class intervals 10 - 15 and 15 - 20 taken together to that of the students in the class intervals 5 - 10 and 25 - 30 taken together?

A

15 : 13

B

1 : 1

C

17 : 13

D

13 : 15