Answer: Option A.
It is not a function
Explanation:
By definition The domain of the inverse function of f(x) will be the range of the function f(x).
That is, if the point (3, 4) belongs to f(x), then the point (4, 3) belongs to the inverse of f (x).
Then, we know that a relation is defined as a function if and only if for each input value x there is only one output value y.
Note that the function f(x) has the following points:
(4, 5) (5, 5).
Then, the inverse function will have the following points:
(5, 4) (5, 5)
Note that the inverse function has two different output values for the same input value x = 5.
Therefore the inverse of the function shown in the image is not a function.