In your notebook, set up the following addition using a vertical format and find the sum of the given polynomials. 2 mn + 4 n^2 and 5 m^2 - 7 mn
A) 9 m^2 + 9 mn - 4 n^2
B) 5 m^2 - 14 mn - 4 n^2
C) 5 m^2 - 5 mn + 4 n^2
D) 5 m^2 + 5 mn - 4 n^2