The correct option is A 0
We have, y=cos x3
Let u=x3,
Differentiating u w.r.t x, we get
dudx=3x2
Also, y=cosu
Differentiating w.r.t u,
dydu=−sinu
As we know by chain rule,
dydx=dydu⋅dudx
dydx=−sinu⋅3x2
dydx=−(sinx3)⋅3x2
∣∣∣dydx∣∣∣x=0=(sin0)⋅3×0=0
So, option A is correct.