The correct answer is: None of these
The distance between two automatic signals can vary depending on a number of factors, including the type of road, the speed limit, and the traffic volume. In general, however, the distance between two automatic signals is typically between 1 and 2 kilometers.
Option A: 2 km. This is a common distance between two automatic signals,
but it is not always the case. For example, in areas with high traffic volume, the distance between two automatic signals may be shorter.Option B: 1 km. This is a shorter distance than is typically used between two automatic signals. However, it may be used in areas with low traffic volume or where there is a need to reduce the speed limit.
Option C: 3 km. This is a longer distance than is typically used between two automatic signals. However, it may be used in areas with high speed limits or where there is a need to increase the distance between two automatic signals.
Option D: None of these. This is the correct
answer because the distance between two automatic signals can vary depending on a number of factors.