How far ahead must you signal when turning or changing lanes?

Answer: B — 50-100 feet

When turning or changing lanes, it is important to signal at least 50-100 feet before making the maneuver. This distance allows other drivers to be aware of your intentions and gives them enough time to react accordingly. Options A and C are incorrect because 15-50 feet and 100-200 feet, respectively, may not give other drivers enough time to adjust their speed or position. Option D is also incorrect because signaling too early, at 200-300 feet, could potentially confuse other drivers if there are multiple turns or lanes in that distance. Therefore, it is important to signal within the range of 50-100 feet for safe and effective communication with other drivers on the road.