At Anywhere High, there are 470 students, of which 223 are boys. There are 75 girls in athletics, and 157 boys who are not. Of the 75 girls in athletics, 31 of them ride the bus, and the total number of girls who ride the bus is 100. 25 boys who are in athletics ride the bus out of the 203 total students who ride the bus.

a) 68 girls don't ride the bus.
b) 213 boys don't ride the bus.
c) 142 girls don't participate in athletics.
d) 172 boys don't participate in athletics.