If True, Which of the Following Would Be Most Important

If true, which of the following would be most important in determining whether? P. chromatophora's cyanelle is still an endosymbiont, or is an organelle, as the term cyanelle implies?

A) if P. chromatophora is less fit without its cyanelle than with it
B) if the cyanelle is less fit without the host cercozoan than with it
C) if there is ongoing metabolic cooperation between the cyanelle and the host cercozoan
D) if the magnesium-containing porphyrin ring in the cyanelle's chlorophyll molecules is built by the cyanelle, whereas the organic portion of the chlorophyll molecules is built by the host cercozoan
E) if there has been movement of genes from the cyanelle genome to the nuclear genome, such that these genes are no longer present in the cyanelle genome