[Mike Simonds]

NFHS rules: Key point to remember: The location of the ball (not the player) relative to the goal line determines whether you have a touchdown, touchback, or safety.

A) As long as the ball did not break the plane of the goal line it remains live even if the receivers foot (or feet) is touching the goal line.

B) R muffs the ball, therefore it remains a kick, and kicks that break the plane of R's goal line result in touchbacks.

C)If R muffs the kick and it remains in the field of play, K may recover it.

D)Same answer as B): Touchback.