For the image below, the answer is C. However, why is there no centripetal force **at point R** acting towards the center to give it a centripetal acceleration, such that the resultant acceleration vector is pointing down and to the left (or southwest) when both gravity and the centripetal force are accounted for?
[![enter image description here][1]][1]


  [1]: https://i.sstatic.net/YzTPg.png