When passing another vehicle, pedestrian, or bicyclist you should assume that

Answer: D — They may move into your traffic lane

When passing another vehicle, pedestrian, or bicyclist, it's important to remember that they may move into your traffic lane. This is why you should always leave enough space while passing to account for any sudden movements from the other person. Option A is incorrect because the assumption that they are stationary may cause you to not leave enough space for passing. Option B is incorrect because it's not safe to assume that they can see you clearly, as visibility can be affected by various factors such as weather or distractions. Option C is incorrect because right of way depends on the specific situation and should not be assumed while passing. Therefore, option D is the most important consideration when passing another person or vehicle.