Final answer:
Driving 20 mph over the speed limit in a school zone is an example of reckless operation speed in Washington State, due to the significant danger posed in areas where children are present.
Step-by-step explanation:
The scenario that exemplifies reckless operation speed in Washington State among the choices provided is driving 20 mph over the speed limit in a school zone. Generally, exceeding the speed limit by a significant margin, especially in areas with heightened safety concerns, such as school zones, is often considered reckless. Additionally, Washington State law may apply stricter penalties for speeding in a school zone because of the potential increased risk to children. On the other hand, driving 10 mph over in a residential area or 5 mph over on a highway might not fall under the definition of reckless depending on circumstances, but driving 20 mph over in a school zone is typically beyond acceptable limits and is likely to be seen as reckless driving. It's worth noting that driving at the speed limit, as in scenario 4, is, by definition, not considered reckless.