Direction to be followed (D1) “The sign indicates that the vehicle may only be driven in the direction of the arrow or, in the case of two arrows, in either arrow’s direction. The symbol is adapted to the conditions of the location.”
One-way traffic (E16) “The sign indicates that vehicle traffic on the road is one-way in the direction of the arrow.”
Run-through of the alternative answers:
There can be no traffic coming from the right, because the road on the right is one-way.
– Wrong. There may be traffic coming from the right. Although the road to the right is one-way, the traffic may come from the right, but not from the left.
I must turn left, because the road straight ahead is one-way.
– Wrong. You do not need to turn left, as you can also continue straight ahead. The road straight ahead is one-way for traffic in your direction of travel.
I must give way to traffic from the right, and I may not turn right.
– Correct. The priority-to-the-right rule applies. Both the mandatory sign and the prohibitory sign indicate that you may not turn right.
I must either turn left or continue straight ahead. Traffic coming from the right must give way to me.
– Wrong. You must give way to traffic coming from the right, not the other way around. It is, however, true that you must turn left or continue straight ahead.