A.Pierre had announced his success prematurely.
B.The investigation of Pierre's expedition wasn't thorough.
C.Pierre wasn't an experienced explorer.
D.He had reached the pole before Pierre did.
A.They talked to one of Pierre's companions.
B.They interviewed Pierre.
C.They conducted a computer analysis of photographs.
D.They examined Pierre's navigation tools,
A.Dr. Cook's expedition.
B.The conclusions of the Navigation Foundation.
C.Exploration of the Equator.
D.Exploration of the South Pole.