What are the four components of a DUI investigation?

Answer: B — At least one car length

When merging onto a freeway, you should give at least one car length of space between your vehicle and the vehicles already on the freeway. This allows for a safe merging maneuver and gives enough room for both vehicles to adjust their speed if needed. Option A, none, is incorrect because merging onto a freeway without giving enough space can cause an accident or force other drivers to suddenly change lanes. Option C, the distance of one block, is incorrect because this distance can vary greatly depending on the length of a block and may not be a safe distance for merging. Option D, the length of two cars, is also incorrect as this may not leave enough space for a seamless merge and can create a potential hazard on the freeway.