Which of the following statements concerning speed limits on the open road in NC is correct?

In North Carolina, the general speed limit for passenger cars on highways is indeed 55 mph unless otherwise posted. The common misconception that it's 65 mph could lead to confusion, as certain highways have higher posted limits, but the default in most instances is lower. Regarding school activity buses, while they usually have a lower speed limit of 35 mph when passing a school or while in school zones, they may not be restricted to that speed limit on all open roads. Therefore, it's important to recognize that neither of the provided statements accurately reflects the legal speed limits in North Carolina, which means neither statement stands correct within the context of open road regulations.