All drivers must signal a turn at least _____.

Answer: B — 100 feet before you enter an intersection

The correct answer, which indicates that all drivers must signal a turn at least 100 feet before entering an intersection, is based on the principles of safe driving and communication with other road users. Signaling your intention to turn well in advance is crucial for maintaining safety on the road. It gives other drivers, cyclists, and pedestrians adequate notice of your planned action, allowing them to respond appropriately. By requiring a signal 100 feet before entering an intersection, this guideline helps ensure that others can anticipate your maneuvers, thus reducing the chances of collisions and misunderstandings among road users. Proper signaling is a vital aspect of safe driving practices that ultimately contributes to smoother traffic flow and increases overall safety for everyone on the road.