Ascientist investigated dna replication in two groups of cells, labeled a and b. she injected radioactively labeled nucleotides into cells of each group and allowed dna replication to begin. when replication was halfway completed, she injected a drug into the cells to stop replication. she then examined the cells to determine the distribution of the newly-synthesized dna. she found each cell of group a had many segments of new dna in its nucleus, while each cell of group b had a single segment of new dna in its cytoplasm. what can the researcher conclude about the cells? a. group b cells are eukaryotic because they must have a single origin of replication. b. the cells in group a are eukaryotic because they replicate their dna in the cytoplasm or nucleus. c. group a cells are prokaryotic because they must have many origins of replication. d. the cells in group b are prokaryotic because they replicate their dna in the cytoplasm.