The sign seen in the photograph requires maintaining that maximum speed throughout the entire town...

The sign seen in the photograph requires maintaining that maximum speed throughout the entire town...
A)regardless of any other speed signs found within it.
B)being able to exceed it by 20 km/h to overtake.
C)except where another speed is indicated.Correct
Regulatory signs placed beside or directly above a sign indicating the name of a town mean that the regulation applies throughout the entire town, unless a different regulation is indicated within the town by other signs on certain sections of the road.

The general speed limits on urban roads, depending on the characteristics of the carriageway, are as follows:
a) 20 km/h on roads with a single shared platform for carriageway and pavement.
b) 30 km/h on roads with a single lane per direction of travel.
c) 50 km/h on roads with two or more lanes per direction of travel. (40 km/h for vehicles transporting dangerous goods)
For these purposes, lanes reserved for certain users or for the exclusive use of public transport shall not be counted.
These limits may be reduced or increased by the Municipal Authority subject to specific signage.
On through roads within towns, a limit of 50 km/h is set for all types of vehicles, except for vehicles transporting dangerous goods, for which it shall be 40 km/h. This limit may be reduced by agreement between the Municipal Authority and the road authority, subject to specific signage.