The vertices changed this way:
(1,1) ---- (transformation) ---> (2,4)
(4,1) ---- (transformation) ---> (8,4)
(4,3) --- (transformation) --- > (8,8)
See that in the transformation he made 2 times in x and y coordinate, then added +2 in the y coordinate. Thus, we can make the inverse path. Dilation by a factor of 1/2 in both coordinates followed by a translation down 2 units in the y coordinate.
Then the answer is the letter A.