Cara has driven one-fifth of the total distance, d, to her destination. Which statement explains why both 1/5d and 0.2d can find the distance she has driven?

Because 0.2 is 1/5 in decimal form!

Cara has driven one-fifth of the total distance, d, to her destination.

In fraction form one-fifth is 1/5

If we divide 1 by 5 we get decimal as 0.2

So we can say that both 1/5 and 0.2 are same.

So this statement explains why both 1/5d and 0.2d can find the distance she has driven:

0.2d is decimal equivalent of 1/5d.