When Researchers Rumpho and Manhart Looked at the Genomes of Sea

When researchers Rumpho and Manhart looked at the genomes of sea slugs and chloroplasts,what hypothesis were they testing?

A) that only photosystem II is necessary for photosynthesis
B) that some sea slug genes were present in chloroplast chromosomes
C) that the sea slugs have to continuously consume chloroplasts to replace the older ones
D) that chloroplasts can function without some proteins involved in photosynthesis
E) that some chloroplast genes were present in the sea slug chromosomes