MY BRAIN CANNOT NOT THINK HARD ENOUGH TO ANSWER THIS!!!! HEEELP :( 17 points which is all my points if you help!!!

Answer:
That would be C, 9:25
Step-by-step explanation:
That is because you would dividing the number of boys over number of girls riding bikes. 45/125. Then in simplest form, the fraction will be 9/25, meaning in ratio it is 9:25
Hope it helps:)