We are given the graph of the function f(x) and asked to identify which one is the graph of f(x)-1.
Note that as we are subtracting 1 from the value of the function f and not to the argument, it means that we are applying a shift to the graph. As we are subtracting from the value, this is a vertical shift. Also, as we are subtracting, the shift is downwards.
So the graph of f(x)-1 is the same graph of f(x) but shifted 1 unit down which corresponds to option B
