Assertion (A) and Reason (R)
(A) Both A and $\mathrm{R}$ are true and $\mathrm{R}$ is the correct explanation of $\mathrm{A}$.
(B) Both $\mathrm{A}$ and $\mathrm{R}$ are true but $\mathrm{R}$ is not the correct explanation of $\mathbf{A}$.
(C) $\mathrm{A}$ is true, $\mathrm{R}$ is false.
(D) $\mathrm{A}$ is false, $\mathrm{R}$ is true.
Assertion $(\mathbf{A}):$ If $27 a+9 b+3 c+d=0$, then the equation $f(x)=4 a x^{3}+3 b x^{2}+2 c x+d=0$ has at least one real root Iying between $(0,3)$. Reason $(\mathrm{R}):$ If $f(x)$ is continuous in $[a, b]$, derivable in
b) such that $f(a)=f(b)$, then ther exists atleast one point (a, $c \in(a, b)$ such that $f^{\prime}(c)=0$