Let P and Q are points on the parabola y2=4ax with vertex O, such that OP is perpendicular to OQ and have lengths r1andr2 respectively, then the value of
r₁⁴/³ r₂⁴/³ / r₁²/³+r₂²/³ is :
A. 16a²
B. a²
C. 4a
D. None of these