If $$f:ℝ \rightarrow B$$, defined by $$f(x) = x^{2} - 5x + 6$$ is onto, then B =

A

$$\left(-\infty, -1\right)$$

B

$$\left(-\infty, -\frac{1}{2}\right)$$

C

$$ℝ - \left(-\infty, -\frac{1}{4}\right)$$

D

$$[0, \infty)$$