How is sand transported in coastal environments by the action of waves? Question 3 options: a) Waves will only move sand up and down the beach along the steepest slope of the coastline. b) Waves move sand diagonally up (in the direction of the wave) and then down the steepest slope of the beach, having a net transport parallel to the shoreline. c) By the wind that is associated with the wave. d) By underground rivers