Identify the statement that correctly describes light and how it travels? (2 points) select one: a. light waves can travel in a vacuum and travel at a constant speed even if the light source is moving. b. light waves can travel in a vacuum and will travel faster if the light source is moving forward. c. light waves need a medium to travel, and they travel faster if the light source is moving forward. d. light waves need a medium to travel, and they travel at the same speed even if the light source is moving.