Which of the follwoing is always correct?
(A) If $f^{\prime}(x)>0 \forall x$ wherever $f^{\prime}(x)$ exists, then $f(x)$ must be one-one
(B) If $f^{\prime}(x)<0 \forall x$ wherever $f^{\prime}(x)$ exists, then $f(x)$ must be one-one
(C) If $\mid f(x)$ be continuous at $x=a$, then $f(x)$ is also continuous at $\mathrm{x}=\mathrm{a}$
(D) If $f(x)$ is continuous at $x=a, f(A)=2$ and $x=a$ is the point of local minimum of $f(x)$, then $[f(x)]$, where [] denotes gresatest integer function, is also continuous