Rolle's theorem holds for the function $f(x)=x^3+ax^2+\beta x, 1≤x≤2$ at the point $\frac{4}{3}$, the values of $\alpha $ and $\beta $ are :

$\alpha=5, \beta =-8$ $\alpha=-5, \beta =-8$ $\alpha=8, \beta =-5$ $\alpha=-5, \beta =8$

$\alpha=-5, \beta =8$