Final answer:
The propaganda film about the Nazi Party rally in Nuremberg in 1934 was called Triumph of the Will and was directed by Leni Riefenstahl.
Step-by-step explanation:
The name of the propaganda film about the Nazi Party rally in Nuremberg in 1934 was Triumph of the Will. It was directed by Leni Riefenstahl, a German filmmaker, and is considered an important step in the development of cinematic technique and the documentary form. The film depicts Adolf Hitler arriving at the 1934 Nuremberg rally and was intended to promote Nazi ideology and glorify the party.