The correct answer is: C. Both
A distant signal is a railway signal placed some distance in advance of a main signal to warn the driver of the train that the main signal is at danger. It is usually placed at a distance of 1,000 to 1,500 feet (300 to 460 m) from the main signal.
Under approved special instructions, a distant signal can be placed along with the last stop or the first stop. This is done to provide additional warning to the driver of the train that the main signal is at danger.
The following are some of the reasons why a distant signal may be placed along with the last stop or the first stop:
- To provide additional warning to the driver of the train that the main signal is at danger.
- To allow the train to slow down more gradually before reaching the main signal.
- To prevent the train from passing the main signal at danger.
It is important to note that the placement of a distant signal along with the last stop or the first stop is done on a case-by-case basis, and it is always subject to the approval of the railway authorities.