A solid sphere is in rolling motion. In rolling motion a body possesses translational kinetic energy $(K_t)$ as well as rotational kinetic energy $(K_r)$ simultaneously. The ratio $K_t : (K_t + K_r)$ for the sphere is :

Question

( A ) 10 : 7
( B ) 2 : 5
( C ) 5 : 7
( D ) 7 : 10