Are vehicles obliged to facilitate overtaking?

A)No.
B)Yes, normally by keeping to the right.Correct
C)Yes, by activating the right turn signal or moving the arm back and forth.
As soon as we notice that the vehicle following us wants to overtake, we are obliged to keep close to the right edge of the roadway, without invading the verge, and we must not change the speed at which we are travelling, although we should reduce it if a dangerous situation arises, unless the overtaking driver reduces theirs, having to make it easier for them to return to their lane.
The driver of the vehicle being overtaken is forbidden to increase speed or carry out manoeuvres that prevent or hinder the overtaking.
Drivers of heavy vehicles, large vehicles or those required to comply with a specific speed limit, must slow down or pull over to the verge as soon as possible, if practicable, to make way for those following them when the density of oncoming traffic, the insufficient width of the roadway, or its profile or condition, do not allow them to be overtaken easily and without danger.
If these drivers cannot keep completely to the right edge of the roadway, but the overtaking can nevertheless be carried out safely, they will indicate the possibility of doing so to the approaching vehicle by extending their arm horizontally and moving it back and forth several times, or with the right turn signal.
The driver of the vehicle being overtaken is forbidden to increase speed or carry out manoeuvres that prevent or hinder the overtaking.
Drivers of heavy vehicles, large vehicles or those required to comply with a specific speed limit, must slow down or pull over to the verge as soon as possible, if practicable, to make way for those following them when the density of oncoming traffic, the insufficient width of the roadway, or its profile or condition, do not allow them to be overtaken easily and without danger.
If these drivers cannot keep completely to the right edge of the roadway, but the overtaking can nevertheless be carried out safely, they will indicate the possibility of doing so to the approaching vehicle by extending their arm horizontally and moving it back and forth several times, or with the right turn signal.