Problem: the curved surface area of a cylindrical pillar is 264 sq . m and its volume is 924 cub . m . find the ratio of its diameter to its height 
Options: ['a ) 7 : 9', 'b ) 7 : 3', 'c ) 7 : 7', 'd ) 7 : 6', 'e ) 7 : 1']
b