Correct Option: C

As per first graph,
The number of students in Collage A = Total number of students x 21%
As per second graph,
The number of girls from College A = Total number of girls x 23%
So number of boys in Collage A = The total number of students in Collage A - The total number of girls in Collage A.
Number of boys in college A = 3500 x 21/100 - 1800 x 23/100 = 735 - 414 = 321
Similarly we can get the number of boys from other collages.
Number of boys in college B = 3500 x 9/100 - 1800 x 10/100 = 315 - 180 = 135
Number of boys in college C = 3500 x 33/100 - 1800 x 31/100 = 1155 - 558 = 597
Number of boys in college D = 3500 x 18/100 - 1800 x 11/100 = 630 - 198 = 432
Hence, number of boys in college C has maximum.