The sign applies to...
A)goods transport vehicles exclusively.
B)motor vehicles exclusively.
C)all vehicles whose maximum laden mass exceeds the figure indicated.Correct
The sign in the question prohibits the passage of all vehicles whose laden mass exceeds the figure indicated in tonnes. That is, the weight of the vehicle at that moment.
By contrast, the following sign prohibits the passage of vehicles used for the transport of goods — even when travelling empty — if their maximum authorised mass exceeds the figure shown on the sign.