Assays that were used to study baculovirus DNA replication had to distinguish the plasmid DNA that was originally transfected into the cells from the DNA that was replicated in the eukaryotic cells.Which of the following describes how this was accomplished?

A) Digestion of DNA with a methylation dependent restriction enzyme.
B) Using a southern blot to distinguish the different types of DNA.
C) Using electron microscopy to distinguish the different types of DNA.
D) Using standard agarose gel electrophoresis to measure different sizes of DNA.
E) Measuring the sizes of the large DNA with a pulsed-field gel electrophoresis.