The chord $$PQ$$ of the parabola $$y^2 = x$$, where one end $$P$$ of the chord is at point $$(4, -2)$$, is perpendicular to the axis of the parabola. Then the slope of the normal at $$Q$$ is

A

$$-4$$

B

$$-\frac{1}{4}$$

C

$$4$$

D

$$\frac{1}{4}$$