What is spirogyra in biology

How did the research presented in the article affect scientists' understanding of the evolution of eukaryotes

Which of the following matches the organisms described with the correct domain? a. bacteria--unicellular, eukaryotic organisms with cell walls that do not contain peptidoglycanb. archaea--multicellular, eukaryotic organisms that do not have cell wallsc. eukarya--single-celled and multicellular organisms, with a defined nucleus and a variety of nutritional sourcesd. bacteria--unicellular, eukaryotic organisms that always lack cell walls

Why reason best illustrates why hershey and chase chose to use viruses in their experiment?