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: if the radius of a circle is decreased 20 % , what happens to the area ? 
Options: a ) 10 % decrease , b ) 20 % decrease , c ) 36 % decrease , d ) 40 % decrease , e ) 50 % decrease

Ex Output:
c


Ex Input:
Problem: the area of a parallelogram is 162 sq m and its altitude is twice the corresponding base . then the length of the base is ? 
Options: a ) 8 , b ) 9 , c ) 7 , d ) 62 , e ) 2

Ex Output:
b


Ex Input:
Problem: a rectangular circuit board is designed to have a width of w inches , a length of l inches , a perimeter of p inches , and an area of c square inches . which of the following equations must be true ? 
Options: ['a ) 2 w ^ 2 + pw + 2 c = 0', 'b ) 2 w ^ 2 − pw + 2 c = 0', 'c ) 2 w ^ 2 − pw − 2 c = 0', 'd ) w ^ 2 + pw + c = 0', 'e ) w ^ 2 − pw + 2 c = 0']

Ex Output:

b