What does a bicycle lane sign indicate?

Answer: B — designated lane for bicycles only

A bicycle lane sign clearly indicates that the lane is specifically designated for the use of bicycles only. This means that cyclists have a dedicated space to ride safely, separate from motor vehicles and pedestrians. The purpose of such signs is to improve safety for cyclists by ensuring they have a specific area to operate in, reducing the likelihood of accidents involving bicycles and other types of traffic. Having a dedicated lane for bicycles helps promote cycling as a viable transportation option while also encouraging safety and adherence to road rules among all road users. In contrast, other options such as a lane reserved for all vehicles would not serve the specific needs of cyclists and could lead to dangerous situations where bicycles interact with motor vehicles. A parking lane for bikes suggests a space for bicycles to be parked rather than ridden, which does not align with the intention of a bicycle lane. Lastly, a pedestrian-only pathway is meant for foot traffic and would not accommodate bicycles, which could create conflicts between cyclists and pedestrians if they were to share the same space. Thus, the clarity and purpose of the bicycle lane sign in ensuring the safety of cyclists is why this answer is correct.