Task: Question Answering
Input (English): Problem: a monkey ascends a greased pole 18 metres high . he ascends 2 metres in first minute and slips down 1 metre in the alternate minute . in which minute , he reaches the top ? 
Options: a ) 21 st , b ) 22 nd , c ) 33 rd , d ) 24 th , e ) none of these
Output (English): c