Hey there!
Unless the smaller object was rotated 360° (in which case the rotation wouldn't have to be mentioned), you can see that all of the lines are still in the same place and that it wasn't rotated at all. This eliminated any answer option that mentions a rotation, which is A and C.
Also, if you count the units of one of the straight lines – for example, line AB and A'B' – you can see that the smaller object is four times smaller than the larger object. In the case of line AB and A'B', line AB is 8 units long and A'B' is 2 units long. This means that the scale factor is
.
Lastly, the smaller object was moved from its initial location, which would be in the center of the larger object if it wasn't moved after being scaled down.
The answer will be, "a dilation with a scale factor of
and then a translation."
Hope this helped you out! :-)