As a result of dna testing, scientists learned the black death was the pneumonic plague, not the bubonic plague. both the pneumonic plague and the bubonic plague. caused by parasites found in drinking water. caused by parasites such as bed bugs.

       B.     both the pneumonic plague and the bubonic plague.

Explanation:

even if the technique for retrieving ancient DNA improves, you need to know what you’re searching for. There is no way now to search for an unknown hemorrhagic virus.

But the possibility that the Black Death could strike again should give scientists the incentive to keep trying. The similarity of the catastrophes in Athens, Constantinople and medieval Europe suggests that whatever the pathogen is, it comes out of hiding every few centuries. And the last outbreak was its fastest and most murderous. What would it do in the modern world? Maybe we should find it, before it finds us.

polar areas, such as antarctica or the south pole.