Giardia is eukaryotic yet is long thought to lack a mitochondira. Recently, researchers have found that each Giardia cell contains double membrane- bound organelles similar to a mitochondria called mitosomes that lack mtDNA. What is the best explanation for mitosomes?

A) Mitosomes are more advantageous to eukaryotes than mitochondria.
B) Mitosomes evolved from another Giardia organelle that lacked DNA.
C) Mitochondria in Giardia evolved into mitosomes and have lost or transferred their DNA to the Giardia nuclear genome.
D) Giardia are asexual and thus do not require mitochondria with its own DNA.
E) Mitosomes are the ancestral form of the mitochondria.