The tangent PT and the normal PN to the parabola $$y^2 = 4ax$$ at a point P on it meet its axis at points T and N, respectively. The locus of the centroid of the triangle PTN is a parabola whose

A

vertex is $$\left(\frac{2a}{3}, 0\right)$$

B

directrix is x = 0

C

latus rectum is $$\frac{2a}{3}$$

D

focus is (a, 0)