In this task, you need to provide the correct option for a given problem on probability from the provided options.

Ex Input:
Problem: if two integers x , y ( x > y ) are selected from - 10 to 4 ( inclusive ) , how many possible cases are there ? 
Options: a ) 150 , b ) 180 , c ) 190 , d ) 210 , e ) 105

Ex Output:
e


Ex Input:
Problem: a question paper has 2 parts , a & b , each containing 8 questions . if a student has to choose 8 from part a & 4 from part b , in how many ways can he choose the questions ? 
Options: a ) 110 , b ) 70 , c ) 120 , d ) 130 , e ) 140

Ex Output:
b


Ex Input:
Problem: what is the probability of getting atmost one head when two unbiased coin are tossed ? 
Options: a ) 3 / 4 , b ) 3 / 2 , c ) 4 / 3 , d ) 1 / 2 , e ) 2 / 6

Ex Output:

a