ALGEBRA HELP PLEASE?!

A group of art students are painting a mural on a wall. The rectangular wall has deminsions of (6x+7) by (8x + 5) and are planning on the mural to be (x+4) by (2x+5). What is the area of the remaining wall after the mural has been painted?

A: 46x^2 + 73x + 15

B: 48x^2 + 86x +35

C: 2x^2 + 13 + 20

D: 50x^2 + 99x + 55