A girder of uniform section and constant depth is freely supported over a span of 3 metres. The point load at the midpoint is 30 kN and Momentof inertia = $$15 \times 10^{-6} m^4$$ and youngs modulus = 200 GN/m$$^2$$. The deflection at centre will be

A

6.6 cm

B

8.6 cm

C

5.6 mm

D

6.6 mtr