Task: Question Answering
Input (English): Problem: a gardener wants to plant trees in his garden in such a way that the number of trees in each row should be the same . if there are 7 rows or 6 rows or 4 rows , then no tree will be left . find the least number of trees required 
Options: a ) 22 , b ) 84 , c ) 28 , d ) 76 , e ) 21
Output (English): b