Which of the following is true about volcanic eruptions? A. Volcanic eruptions never act as constructive forces because they do not build up landforms. B. Volcanic eruptions act as constructive forces when volcanic gases cause acid rain that weathers rocks. C. Volcanic eruptions act as constructive forces when lava builds up to form volcanoes and plateaus. D. Volcanic eruptions act as constructive forces when they blast away the sides of volcanoes.