The correct answer is: A. Either side points.
When a running line is blocked by a stabled load, the points to be set against are either side points. This is to prevent any trains from running into the stabled load. The points should be set against the running line so that the train will be diverted onto the siding.
The rear points are the points that are located at the rear of the train. They are used to direct the train into the siding. The advance points are the points that are located at the front of the train. They are used to direct the train onto the running line.
If the points are not set against the running line, there is a risk that a train could run into the stabled load. This could cause a derailment and serious injuries or death.
It is important to always set the points against the running line when a running line is blocked by a stabled load. This will help to prevent accidents and keep everyone safe.