Which method is effective for increasing a cyclist's visibility to motorists?

Wearing reflective gear and using lights significantly enhances a cyclist's visibility to motorists, making it the correct choice. Reflective gear helps to reflect light from vehicle headlights, allowing drivers to see cyclists more easily in low-light conditions or at night. Similarly, using front and rear lights not only provides illumination but also alerts drivers to the cyclist's presence on the road. This combination increases the overall visibility and safety of cyclists in various environments, particularly in urban areas where traffic can be dense.

In contrast, riding in the gutter may not be effective for visibility; it could place cyclists in a position that is less noticeable and more dangerous, especially if vehicles are passing closely. Riding with an umbrella can obstruct visibility and balance, creating a hazard rather than increasing safety. Wearing all black clothing reduces visibility, especially at night or in poorly lit conditions, making it much harder for motorists to spot the cyclist. Thus, the use of reflective gear and lights emerges as the safest and most effective method for increasing a cyclist's visibility to motorists.