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: what should be added to 4329 so that it may become a perfect square ? 
Options: a ) 24 , b ) 25 , c ) 26 , d ) 27 , e ) 28

Ex Output:
d


Ex Input:
Problem: an equilateral triangle and three squares are combined as shown above , forming a shape of area 48 + 4 √ 3 . what is the perimeter of the shape formed by the triangle and squares ? 
Options: ['a ) 18', 'b ) 27', 'c ) 36', 'd ) 48', 'e ) 64']

Ex Output:
c


Ex Input:
Problem: in a rectangular coordinate system , what is the area of a rhombus whose vertices have the coordinates ( 0 , 3.5 ) , ( 10 , 0 ) , ( 0 , - 3.5 ) , ( - 10 , 0 ) ? 
Options: a ) 56 , b ) 88 , c ) 70 , d ) 116 , e ) 120

Ex Output:

c