How do modern methods historians investigate the black death?

modern methods allow historians to throw out old records that were incorrect.
modern methods allow the publishing of findings to reach other investigators.
modern methods allow the testing of victims’ bodies using new technology.
modern methods can prevent the plague from ever happening again.

The answer is C. Modern methods allow testing of victims bodies using new technology

genetics is the study of how dna works, the methodologies defining the new recent technologies allow scientist to have a panoramic view of the entire dna landscape, especially how genomes interact with their environment, including off course, factors outside their organisms.

thus is very possible the existence of both scenarios, where populations of isolated individuals have different genetic traits, and share traits related to genetic mutation, due rats can easily travel overseas using human transport channels. so scientists could get a vast number of data, including human interaction, evolution of rodents, health development, spread of infections, development of new organisms, how genomes evolve in different environments and so on.