challenge: Who were the two Italian drivers that first appeared with the Ferrari 312 PB at the 1971 1000 km of Buenos Aires?
  
  A. Ignazio Giunti and Clay Regazzoni
  B. Ignazio Giunti and Jacky Ickx
  C. Ignazio Giunti and Arturo Merzario
  D. Arturo Merzario and Mario Andretti
  Answer: 