Solve this:

1.  A solid sphere of uniform density and radius R applies a gravitational force of attraction equal to F₁ on a particle placed at a distance 2R from the centre of the sphere. A spherical cavity of radius R/2 is now made in the sphere as shown in the figure The sphere with cavity now applies a gravitational force F₂ on the same particle. The ratio F₂/F₁ is

(A) 5/9                                               (B) 7/8
(C) 3/4                                               (D) 7/9