What is the minimum distance we should keep from the vehicle ahead inside a tunnel?

A)That which allows us to brake without colliding with the vehicle ahead.
B)At least 100 metres.Correct
C)At least 150 metres.
In tunnels or underpasses, when not intending to overtake, a safety distance from the preceding vehicle of at least 100 metres or a minimum time interval of four seconds must be maintained at all times.
For vehicles with a MAM exceeding 3,500 kg, the safety distance to be kept will be at least 150 metres or a minimum interval of 6 seconds.
Remember that overtaking is prohibited in tunnels, unless we have more than one lane in our direction.
The following sign reminds us of the general safety distance we must keep.
For vehicles with a MAM exceeding 3,500 kg, the safety distance to be kept will be at least 150 metres or a minimum interval of 6 seconds.
Remember that overtaking is prohibited in tunnels, unless we have more than one lane in our direction.
The following sign reminds us of the general safety distance we must keep.