At x = 0, y = 5.
At x = 1, y = 10.
At x = 2, y = 20.
At x = 3, y = 40.
y is greater than 50 before x reaches 3.5.
If we check each choice:
A cannot be true, or else the y-values should be increasing by 10 each month (ex. 10, 20, 30, 40, 50).
B cannot be true, or the y-values would be decreasing.
C cannot be true, or the y-values should be increasing much faster (ex. 10, 100, 1000, 10000)
D is true, since the y-values are doubling (5, 10, 20, 40).
So the correct answer is D.
