You are driving along a narrow avenue. What must you be aware of?

The selected combination is correct because it encompasses essential safety considerations when driving on narrow avenues.

1. Stopping within half the visible distance is crucial to avoid accidents, as it ensures that you can react in time to unexpected obstacles or vehicles.

2. Stopping for oncoming traffic, if necessary, reflects the principle of yielding in confined spaces, which is important to allow safe passage to other road users.

3. Anticipating unevenness at the edge of the road due to tree roots is important for vehicle control and safety, as it can affect stability and potentially lead to accidents.

By choosing all three options, you show an understanding of the multifaceted challenges posed by narrow roadways as outlined in German traffic regulations, which prioritize both safety and courtesy on the road.