challenge: What were the National Protest Days (Jornadas de Protesta Nacional) that Mauricio Hernández Norambuena participated in?
  
  A. A series of strikes by marine biologists against environmental pollution
  B. A wave of protests in the 1970s against the Chilean government
  C. A communist-led movement to promote social welfare programs
  D. A student-led movement to reform the education system in Chile
  Answer: 