Task: Question Answering
Input (English): Problem: a man â € ™ s current age is ( 2 / 5 ) of the age of his father . after 10 years , he will be ( 1 / 2 ) of the age of his father . what is the age of father at now ? 
Options: a ) 40 , b ) 45 , c ) 38 , d ) 50 , e ) 39
Output (English): d