challenge: What is the total area of Concord, Nebraska, according to the United States Census Bureau?
  
  A. 0.13 square miles (0.34 km2), all land
  B. 0.34 square miles (0.13 km2), all land
  C. 0.13 square kilometers (0.34 km2), all land
  D. 0.34 square kilometers (0.13 km2), all land
  Answer: 