Final answer:
The graph of f(x) is a horizontal line, which fails the horizontal line test, indicating that f(x) does not have an inverse function.
Step-by-step explanation:
To answer the question of whether the function f(x) has an inverse, we must consider the horizontal line test. If any horizontal line intersects the graph of the function at more than one point, then the function does not have a unique inverse because it is not one-to-one. From the description, it seems that the graph of f(x) is a horizontal line, which means it fails the horizontal line test. Therefore, option C is correct: f(x) does not have an inverse function because its graph fails the horizontal line test. It is important to note that the vertical line test is used to determine if a graph represents a function, while the horizontal line test is used to determine if a function has an inverse.