Answer:
D: (x,y) -> (2x, 2y)
Step-by-step explanation:
Take a look at the top of the roof, in the small house it is at (6,4) and in the big house it is at (12, 8).
To get from (6,4) to (12,8) you have to multiply x and y by 2.
You can test this with multiple points. Only the (x,y) -> (2x, 2y) mapping works for all of them.
