SajjadAhmad
What is the unit area of circle O on the standard xy-coordinate plane?
I have no idea what "unit area" means -- does it mean something different from just "area"? The term is especially confusing in this context, because when we talk in coordinate geometry about the "unit circle", we specifically mean the circle of radius 1, centred at the origin. So that's what the question appears to be describing at first, but looking at Statement 1, the circle cannot be the unit circle. It's hard to answer math questions when it's unclear what they're asking - what is the source?
Anyway, assuming they just want ordinary area, two points do not define a unique circle (three points do), so Statement 1 is not sufficient. Statement 2 is clearly not sufficient alone. Using both, RS is a diameter, and we can find its length, so we can compute the circle's area, and the answer is C.