Unlike Virtually All Other Eukaryotes, Diplomonads Lack Mitochondria

Multiple Choice

Unlike virtually all other eukaryotes, diplomonads lack mitochondria. Why aren't these organisms considered to represent a state most like the common ancestor to all other eukaroyotes?

A) They have endosymbiotic relationships with other bacteria.
B) They do not use ATP to power their cells.
C) They have non-functional mitochondrial remnants.
D) They are phototrophic.