A is the correct choice.
This is based on the vertical line test. If you were to draw an imaginary vertical line on the graph, it would only intersect the graph at one point, which proves that all x values are different (a function).
Q+P =180 so (Q is 137) p=s so (s is 43) and q = r so (r is 137)
We'll have an attached picture (Ignore the labeling). We can easily observe that DF (in the picture BC), cannot be equal to the radius. Then, we cannot also claim that RD=RF. And since we are talking about the tangent segment, we'll have a right triangle. The correct answer is C)