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 length and breadth of a rectangle is increased by 10 % and 30 % respectively . what is the increase in the area ? 
Options: a ) 43.0 , b ) 44.0 , c ) 43.5 , d ) 45.0 , e ) 42.0

Ex Output:
a


Ex Input:
Problem: three interviewers , a , b , and c are interviewing 30 applicants . only with three interviewers ' admission can an applicant be admitted . if interviewer a admitted 10 applicants , b admitted 12 applicants , and c admitted 15 applicants , at least how many applicants get the admission ? 
Options: a ) 6 , b ) 2 , c ) 0 , d ) 8 , e ) 12

Ex Output:
c


Ex Input:
Problem: the circus sells two kinds of tickets : lower seats for $ 30 and upper seats for $ 20 . on a certain night , the circus sells 80 tickets and gets $ 2100 in revenue from the sales . how many tickets for lower seats did they sell ? 
Options: ['a ) 40', 'b ) 45', 'c ) 50', 'd ) 55', 'e ) 60']

Ex Output:

c