线3x + 4y + 2 = 0与圆x2 + y2 + 4x = 0交于A,B两点,则线段AB的垂直平分线的方程是 ( )
A 4x-3y-2 =" 0 " B 4x-3y-6 =" 0"
C 4x + 3y + 6 =" 0 " D 4x + 3y + 8 = 0