Which of the following is true about signaling?

Only the driver may make hand signals, not the passengers. Car drivers should use hand signals whenever they are more visible than turn signals. When the sun is low in the sky, the sun's light may reflect off the turn signal lenses, making the turn signals hard to see. At night, signal lights are easier to see than hand signals. The driver of a large vehicle such as a tractor-trailer is required to use turn signals because hand signals can be obscured by the vehicle's bulk. [Hand Signals, Defensive Driving Skills, Chapter 4 – Your Driving, North Carolina Driver's Handbook], [NC G.S. § 20-154]