Task: Question Answering
Input (English): Problem: the total number of plums that grow during each year on a certain plum tree is equal to the number of plums that grew during the previous year , less the age of the tree in years ( rounded down to the nearest integer ) . during its 4 th year , the plum tree grew 50 plums . if this trend continues , how many plums will it grow during its 6 th year ? 
Options: a ) 36 , b ) 41 , c ) 38 , d ) 40 , e ) 42
Output (English): b