What do these signs indicate to you?
A)That from the sign onwards urban area rules apply and that the circulation of trucks is prohibited.Correct
B)That trucks must travel at 50 km/h.
C)That the circulation of trucks of more than 3.5 T MAM is prohibited.
Regulatory signs placed next to or vertically with a sign indicating the name of a town indicate that the regulation applies throughout the town, unless within the town a different regulation is indicated by other signs on certain stretches of road.
In the case of the question, the signs indicate the prohibition, from the town entrance sign, of the circulation throughout the municipal area of vehicles intended for the transport of goods, understood as such trucks and vans, regardless of their mass.