Read the paragraph from the section "Economics and society." What conclusion can the reader make based on this paragraph? "Between 1347 and 1350, however, a mysterious disease started to spread across Europe. It was called the bubonic plague, though many at the time called it the "Black Death." It killed about 20 million people in Europe or about 1 out of every 3 people. It was especially deadly in cities. People were so crowded together there that it was impossible to prevent the disease from spreading.

1. The bubonic plague was caused by serfs who moved into cities.
2. People who lived in the countryside were safe from the bubonic plague.
3. Fewer people may have died from bubonic plague if serfs had stayed in the country.
4. Rulers and wealthy people were less affected by bubonic plague than peasants were.