From this sign onwards...

A)It is advised not to exceed 20 km/h and pedestrians will have priority.
B)It is prohibited to exceed 10 km/h and pedestrians will have priority.Correct
C)As it is a residential street, the maximum speed will be 30 km/h.
The sign in the question, "Residential and play zone", indicates specially conditioned circulation areas that are intended primarily for pedestrians and where the following special traffic rules apply:
- The maximum speed of vehicles is set at 10 kilometers per hour;
- Drivers must give priority to pedestrians;
- Vehicles can only park in places designated by signs or markings;
- Cycles and, where applicable, PMVs, may circulate in both directions, unless the competent authority establishes otherwise;
- Pedestrians may use the entire circulation area, and therefore pedestrian crossings are not signposted;
- Games and sports are permitted in the area. It will always be accompanied by the R-301 sign which will limit the speed to 10 km/h.
- The maximum speed of vehicles is set at 10 kilometers per hour;
- Drivers must give priority to pedestrians;
- Vehicles can only park in places designated by signs or markings;
- Cycles and, where applicable, PMVs, may circulate in both directions, unless the competent authority establishes otherwise;
- Pedestrians may use the entire circulation area, and therefore pedestrian crossings are not signposted;
- Games and sports are permitted in the area. It will always be accompanied by the R-301 sign which will limit the speed to 10 km/h.