The correct option is A (a−2)
a3−5a2+10a−8)a3−4a2+7a−6(1 a3−5a2+10a−8 − + − +––––––––––––––––––––––– a2−3a+2
a2−3a+2)a3−5a2+10a−8(a−2 a3−3a2+2a − + −–––––––––––––––– −2a2+8a−8 −2a2+6a−4 + − +–––––––––––––––––––– 2a−4
2a−4=2(a−2)
a−2)a2−3a+2(a−1 a2−2a − + ––––––––––––––– −a+2 −a+2 + − –––––––––––– 0
So, GCD of (a3−4a2+7a−6) and (a3−5a2+10a−8) is (a−2).