Due to the fall of the Soviet Union.
Answer: its b
Explanation: The bacterium that causes the bubonic plague is called yersinia pestis. It can survive in rodent populations and is spread to other mammals, including humans, through flea bites. ... The 1330s outbreak also spread west across Central Asia via traders using the Silk Road.
Two things that increased american interchanges in the late 1800s were "b. the telegraph and telephone," since both of these creations significantly accelerated correspondence and made it more productive.
