Given the task definition and input, reply with output. In this task, you need to provide the correct option for a given problem from the provided options.

Problem: in a group of 28 junior high school students , 7 take french , 10 take spanish , and 2 take both languages . the students taking both french and spanish are not counted with the 7 taking french or the 10 taking spanish . how many students are not taking either french or spanish ?
Options: a ) 7 , b ) 6 , c ) 9 , d ) 4 , e ) 8
c