challenge: According to the 2021 Census of Population, what was the population density of Saint-Roch-de-Mékinac?
  
  A. 2.1/km2 (5.4/sq mi)
  B. 3.0/km2 (7.8/sq mi)
  C. 2.5/km2 (6.5/sq mi)
  D. 1.5/km2 (3.9/sq mi)
  Answer: 