Why might the process of chemotaxis in the archaeon Halobacterium be similar to chemotaxis in Bacteria?

A)Similar proteins in the chemotaxis signaling pathway are found in both Halobacterium and Bacteria.
B)The flagellin protein is almost identical in sequence for both Halobacterium and Bacteria.
C)Genes that encode proteins for flagellum assembly are found in both Halobacterium and Bacteria.
D)Both Halobacterium and Bacteria use ATP to turn the flagellum.
E)Fagellum assembly is identical in both Halobacterium and Bacteria.