plzz help i tried everything, dose anyone know where i can get the answer key to AP. EX learning sociology class? ;

Technician a says the harmonic balancer may be attached to the crankshaft using a woodruff key and center bolt. technician b says the harmonic balancer may be attached to the crankshaft using a square key and center bolt. who is correct? choose one answer. a. technician a b. technician b c. both technician a and technician b d. neither technician a nor technician b