Unless otherwise posted, what is the speed limit on primary and secondary state and federal highways in Tennessee?

Answer: A — 55 mph

In Tennessee, unless otherwise posted, the speed limit on primary and secondary state and federal highways is typically 55 mph. This speed limit is a standard default limit for these types of highways unless signs indicate a different speed limit. It is important for drivers to be aware of and follow posted speed limits to ensure safety on the roadways. Additionally, it is worth noting that the other options provided as choices are not the correct speed limits for primary and secondary state and federal highways in Tennessee.