Which expressions are polynomials? Select each correct answer. 6+w. 2x^4 -y. z+1. y^2 -^3√y +4​

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