For m^3 : Because you are subtracting a negative from a negative, that means you are adding, therefore the first part should be 7m^3
For m^2 : because you are subtracting a positive from a negative, that means you are subtracting, so it would be -11m^2
For m : because you are subtracting a negative from zero, it would turn into a positive, making it just 5
For the constant : subtracting positive 8 from negative 9 makes it a positive from the double negative. Therefore you would add 8+9, giving you 17
FINAL ANSWER : B. (7m^3)-(11m^2)+5m+17
