In the circle with center O above, chord QS is perpendicular to radius

In the circle with center O above, chord QS is perpendicular to radius OR. If QS = 16 and PR = 4, what is the area of the circle ? (A) 80 (B) 100 (C) 125 (D) 144 (E) 256 Spoiler: :: Attachment:Untitled.png