Which of the following equations fits this graph?

Answer: Option A.
Step-by-step explanation:
The equation of the line in slope-intercept form is:
[tex]y=mx+b[/tex]
Where the slope is "m" and the intersection of the line with the y-axis is "b".
Given the function f(x) in the form [tex]f(x)=x[/tex], you can identify that:
[tex]m=1\\b=0[/tex]
This means that the line passes through the origin (0,0)
And from the function g(x) in the form [tex]g(x)=x-4[/tex], , you can identify that:
[tex]m=1\\b=-4[/tex]
This means that the line of the function g(x) and the line of the function f(x) have the same slope, but the line of g(x) passes through the point (0,-4)
Therefore, the graph of f(x) must be shifted 4 units down to produce the graph of g(x)