In this task, you need to answer the given multiple-choice question on geometry. Classify your answers into 'a', 'b', 'c', 'd', and 'e'.

Input: Consider Input: Problem: the diameter of a circle is 4 / . find the circumference of the circle .
Options: ['a ) 8', 'b ) 4 ', 'c ) 4', 'd ) 6', 'e ) 5']

Output: a

Input: Consider Input: Problem: d and e are two points respectively on sides ab and ac of triangle abc such that de is parallel to bc . if the ratio of area of triangle ade to that of the trapezium decb is 144 : 25 and de = 13 cm , then find the length of bc .
Options: ['a ) 5', 'b ) 13', 'c ) 14', 'd ) 11', 'e ) 15']

Output: a

Input: Consider Input: Problem: find the curved surface area , if the radius of a cone is 28 m and slant height is 30 m ?
Options: a ) 2550 , b ) 2640 , c ) 3960 , d ) 4280 , e ) 5490
Output: b