In the middle school band, the ratio of students who play brass to students who were lay percussion is 5 to 2. Which of the following could be the number of students in the band and the number of students who play brass?

A42 band members, 21 brass

B35 band members, 25 brass

C25 band members, 10 brass

D21 band members, 6 brass

Please explain how to give the answer also