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.
Steamboats, introduced in 1807, disrupt the natural environment by the need for fuel lead to deforestation and air pollution.
The first Steamboat, known as the clermont on the Hudson River in 1807, Robert Fulton ad Robert Livingston introduced the first Steamboat. It became the prefered mode of water transportation.
The powerful nations of Europe were ready to formally expand their empires into Asia and Africa. Known as New Imperialism, this desire for expansion was motivated by many things, not the least of which were the promise of economic growth, the sting of national rivalries, and a sense of moral superiority.
A German term for “lightning war,” blitzkrieg is a military tactic designed to create disorganization among enemy forces through the use of mobile forces and locally concentrated firepower.
Its successful execution results in short military campaigns, which preserves human lives and limits the expenditure of artillery.