Add (4a²b - 3ab2 + 2ab + 5) and (2a2b + 3ab2 - 7ab).

A. 6a4b2 - 5ab + 5

B. 6a²b - 5ab + 5

C. 6a2b2 - 5a2b2 - 5

D. 6a²b - 5ab - 5