We would pick points on the graph, substitute the values of x at these points into the equation and find the correponding y values. The function which is satisfied by the x and y values is correct.
On the graph, each interval on the x axis is 1 unit and each interval on the y axis is also 1 unit. Looking at the graph,
where x = - 1, y = 5
For A,
5 = 5^-1
This is not correct
For B,
5 = 5^- -1 = 5^1 = 5
This is correct
If we keep on trying these x and y values on the other functions, they won't satisfy the functions. Thus, the correct answer is B