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

Ex Input:
Problem: the least perfect square , which is divisible by each of 21 , 36 and 66 is
Options: a ) 213414 , b ) 213424 , c ) 213434 , d ) 213444 , e ) none of these

Ex Output:
d

Ex Input:
Problem: a rectangular field has area equal to 150 sq m and perimeter 50 m . its length and breadth must be ?
Options: ['a ) 15 m , 15 m', 'b ) 15 m , 90 m', 'c ) 16 m , 10 m', 'd ) 15 m , 10 m', 'e ) 15 m , 30 m']

Ex Output:
d

Ex Input:
Problem: how many diagonals does a polygon with 23 sides have , if one of its vertices does not connect to any diagonal ?
Options: a ) 201 , b ) 159 , c ) 179 , d ) 189 , e ) 209

Ex Output:
e