Answer: B. Yes because it passes the vertical line test.
Explanation:
Since it is not possible to draw a single vertical line through more than one point on the red curve, this means that the curve passes the vertical line test. This means that any input x leads to exactly one output y. So that's why we have a function here.
Side note: The function doesn't pass the horizontal line test, so this function is not one-to-one.
