will mark brainly if you show work

Choice B
Step-by-step explanation: Hello!
To find the length of KL, we will need to use the distance formula.
The distance formula is \sqrt{(x_{2}-x_{1})^{2} +(y_{2}-y_{1})^{2}}.
We are given K(4, 5) and L(4, -2), and we can find the distance between these two points through substitution.
\sqrt{(4-4)^{2} +(-2-5)^{2}}
\sqrt{(0)^{2} +(-7)^{2}}
\sqrt{(7)^{2}} = \sqrt{49} = 7
Therefore, the length of KL is 7 units, choice B.