Could travelling below the minimum permitted speed be a risk factor?

A)No, because it is always considered an appropriate speed.
B)No, never.
C)Yes, an abnormally reduced speed can cause accidents.Correct
If a driver were to travel below the minimum permitted speed (abnormally reduced speed), they would be impeding the normal flow of other road users, forcing them to overtake at inappropriate moments or places. This is why travelling at such a speed is dangerous and can cause accidents.
Even if there is no specific minimum or maximum speed sign, we must comply with the generic speeds for the type of road and vehicle.
The generic minimum speed on motorways and dual carriageways is 60 km/h, while on all other roads it is half the maximum speed for each type of vehicle.