challenge: Who led the regional government of Piedmont after the 1970 election?
  
  A. Edoardo Calleri di Sala from the Unitary Socialist Party
  B. Gianni Oberto Tarena from the Italian Socialist Party
  C. Gianni Oberto Tarena from the Christian Democracy
  D. Edoardo Calleri di Sala from the Italian Republican Party
  Answer: 