What is the minimum speed limit (in miles per hour) on a two lane undivided highway?

Answer: C — 50 mph

While all other options may be common speed limits for highways, the minimum speed limit for a two lane undivided highway is typically 50 mph. Option A, 30 mph, is a common speed limit for residential areas, but it is too slow for a highway. Option B, 55 mph, is a common speed limit for highways but this is not the minimum. Option D, 45 mph, falls in between the other options but it is still not the minimum speed limit for a two lane undivided highway. Therefore, option C, 50 mph, is the correct answer.