What was one human activity that contributed to the spread of the bubonic plague

The bubonic plague is caused by bacteria called Yersinia pestis. It’s usually spread by fleas. These bugs pick up the germs when they bite infected animals like rats, mice, or squirrels. Then they pass it to the next animal or person they bite. You can also catch the plague directly from infected animals or people.

The plague is believed to be the cause of the Black Death that swept through Asia, Europe, and Africa in the 14th century and killed an estimated 50 million people. This was about 25% to 60% of the European population.

The Black Death was a devastating global epidemic of bubonic plague that struck Europe and Asia in the mid-1300s. The plague arrived in Europe in October 1347, when 12 ships from the Black Sea docked at the Sicilian port of Messina. People gathered on the docks were met with a horrifying surprise: Most sailors aboard the ships were dead, and those still alive were gravely ill and covered in black boils that oozed blood and pus. Sicilian authorities hastily ordered the fleet of “death ships” out of the harbor, but it was too late: Over the next five years, the Black Death would kill more than 20 million people in Europe – almost one-third of the continent’s population.

The bacillus travels from person to person pneumonically, or through the air, as well as through the bite of infected fleas and rats. Both of these pests could be found almost everywhere in medieval Europe, but they were particularly at home aboard ships of all kinds – which is how the deadly plague made its way through one European port city after another.

People just did not know how to avoid the disease at that time and kept in direct contact with the ill ones without any prevention, this situation contributed to the spread of the plague.

i honesty don't know, good luck tho dawg

the correct answwer is d