Given below are two statements: One is labelled as Assertion (A) and the other is labelled as Reason (R).
Assertion (A) : Full thickness prolapse of rectum includes protrusion of all the layers of rectal wall, and is usually associated with a weak pelvic floor.
Reason (R) : The Rectal prolapse is thought to commence as an intussusception of the rectum, which descends to protrude outside the anus.
In the light of the above statements, choose the most appropriate answer from the options given below: