Task: Question Answering
Input (English): Problem: there are 24 students in a seventh grade class . they decided to plant birches and roses at the school ' s backyard . while each girl planted 3 roses , every three boys planted 1 birch . by the end of the day they planted 2424 plants . how many birches and roses were planted ? 
Options: a ) 6 , b ) 7 , c ) 8 , d ) 2 , e ) 9
Output (English): a