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

Ex Input:
Problem: ages of two sisters differ by 9 years . if 5 years ago , the elder one was twice as old the younger one , find their present age 
Options: a ) 1228 , b ) 1423 , c ) 1632 , d ) 1834 , e ) 1932

Ex Output:
b


Ex Input:
Problem: the average of 10 consecutive odd numbers is 22 . what is the sum of the first 3 numbers ? 
Options: a ) 13 , b ) 45 , c ) 17 , d ) 220 , e ) 90

Ex Output:
b


Ex Input:
Problem: if x dollars is invested at 10 percent for one year and y dollars is invested at 8 percent for one year , the annual income from the 10 percent investment will exceed the annual income from the 8 percent investment by $ 38 . if $ 2,000 is the total amount invested , how much is invested at 8 percent ? 
Options: a ) $ 700 , b ) $ 800 , c ) $ 900 , d ) $ 1100 , e ) $ 1200

Ex Output:

c