What is the maximum speed limit in a school zone?

Answer: A — 25 mph

The maximum speed limit in a school zone is 25 mph because there are often children present who may not have the awareness or caution of adults while crossing the road. This speed limit reduces the risk of serious injuries or fatalities in case of an accident. Option B and C are incorrect because these are typical speed limits on regular roads and would be unsafe for a school zone. Option D is also incorrect as it is too slow for regular traffic flow and would cause congestion on the roads. Therefore, option A is the most appropriate answer.