Asurfer is able to stay on the surfboard as she rides the waves. which explains the force(s) that enable her to do this? a. the force of gravity pulls the surfer into the surfboard with enough force to hold her on the surfboard. b. the surfer exerts a force on the surfboard, and the surfboard exerts a force on the surfer that is equal in magnitude and opposite in direction. c. the forward force of the surfboard's acceleration is balanced by the backward force of the surfer's mass. d. the force of friction between the surfer and the surfboard keeps the two traveling together.