contestada

Which of the following is equivalent to the expression below?
(a^2 - 2b^2 + 3) - (4b^2 - 5) + (3a^2 + 4)
A. 4a^2 - 6b^2 + 12
B. 4a^2 - 6b^2 + 2
C. 4a^2 + 2b^2 + 2
D. 4a^2 + 2b^2 + 12