Answer: A point of tangency is M.
Explanation:
1. By definition, a tangent line is that line that intersects the circle at a point, therefore, the point of tangency is the point where the tangent line intersects the circle.
2. Keeping this on mind, you can see in the figure attached that the line that intersects the circle at one point is the line RS and the point where this intersection happens is the point M.
4. Therefore, the answer is the last option.