In a tunnel, if you are driving without intending to overtake, you must keep a distance from the vehicle in front of...

A)that allows the vehicle behind to overtake safely.
B)of at least 100 metres.Correct
C)sufficient to avoid colliding with it in case of sudden braking.
In tunnels, when not intending to overtake, you must at all times maintain a safety distance from the preceding vehicle of at least 100 metres or a minimum interval of four seconds.
Vehicles with a MAM exceeding 3,500 kg must keep at least 150 metres or an interval of 6 seconds as a safety distance.
Vehicles with a MAM exceeding 3,500 kg must keep at least 150 metres or an interval of 6 seconds as a safety distance.