15points+brainliest!! please help !! :)

Answer:
D.
[tex]\sqrt{8}[/tex]
Step-by-step explanation:
[tex](-6,4)=(x_1,y_1)\\\\(-8,6)=(x_2,y_2)\\\\d = \sqrt{\left(x_2-x_1\right)^2+\left(y_2-y_1\right)^2}\\\\d =\sqrt{\left(-8-\left(-6\right)\right)^2+\left(6-4\right)^2}\\\\d = \sqrt{(-8+6)^2 +(6-4)^2} \\\\d = \sqrt{(-2)^2 +(2)^2} \\\\d = \sqrt{4+4} \\\\d = \sqrt{8}\:or\:=2\sqrt{2}[/tex]