Vertex form is

where (h,k) is the vertex.
We can see that the vertex of the graph is at (2,0), and that the graph opens downwards, but does not look stretched at all.
Therefore,
a = -1
h = 2
k = 0
and our vertex form equation is

which is answer A
The answer would be y=x+1
this is the answer because the y-intercept is 1. The line goes by 1/1x. 1/1x is equal to 1x. You can take the 1 out and you will get y=x+1
I hope this helps