Looking at the possible answers, the only one that fits is D.
Let's first look at A: y = 2x
We know this doesn't work, since if you plug in 0 for x, y = 0, not 4.
Let's look at B: 2x^2
We know this doesn't work either, since if x is 0, y = 0, not 4.
Let's look at C: 2 × 2^x
We know this doesn't work, since if x = 0, y = 2:

This leaves D: 4 × 2^x:

It also works for (1,8) and (2,16):


The answer is D.