Final answer:
John Marshall was the only filmmaker mentioned by Tomaselli as being concerned about the Kung's material conditions, with his film 'N/um Tchai: The Ceremonial Dance of the !Kung Bushmen' highlighting this interest.
Step-by-step explanation:
According to Tomaselli, the only filmmaker to be concerned about the material conditions in which the Kung were living was John Marshall. John Marshall's work, specifically the film N/um Tchai: The Ceremonial Dance of the !Kung Bushmen, reflects a deep engagement with and concern for the !Kung people's way of life and their material conditions. His series of films on the !Kung are highly regarded for their ethnographic significance and the unique perspective they offer on the lives of the !Kung people.