Task: Question Answering
Input (English): Problem: two spherical balls lie on the ground touching . if one of the balls has a radius of 7 cm , and the point of contact is 10 cm above the ground , what is the radius of the other ball ( in centimeters ) ? 
Options: a ) 30 / 7 , b ) 50 / 3 , c ) 70 / 4 , d ) 80 / 5 , e ) 90 / 8
Output (English): c