Let $f(x)=\sqrt{x^{2}-4 x+4},$ for $x \in(-\infty, \infty)$. Here, $\sqrt{y}$ denotes the non-negative square root of $y$ when $y$ is non-negative. Then, which of the following is $\text{TRUE}?$
- $f(x)$ is not continuous but differentiable
- $f(x)$ is continuous and differentiable
- $f(x)$ is continuous but not differentiable
- $f(x)$ is neither continuous nor differentiable
- None of the above