When the Black Death spread through Europe, its cause was not understood, so

A. doctors became frustrated and gave up looking for the cause.

B. governments wouldn't allow immigrants to enter each country.

C. many people immigrated to plague-free parts of the world.

D. some groups were blamed and persecuted as a result.

The correct answer is D.

The Black Death was a devastating pandemia which caused the death of between 75 and 200 million people in both Europe and Asia between 1347 and 1351.

At those times, the population was highly influenced by religious beliefs and superstitions. Moreover, the cause of the illness was unknown and this enhanced the terror. It was considered a punishment sent by God due to the existence of disobedience and sinfulness. A human group that was blamed the most were the Jews, who where not believers and hence consider the sinners who were bringing disgrace to the rest. Many prosecutions and pogroms were originated. The catholic religious authorities had to intervene by condemning attack to Jewish people and properties, as Pope Clement VI did in July 1348.

D

Explanation:

The Black Death was a devastating pandemic which caused the death of between 75 and 200 million people in both Europe and Asia between 1347 and 1351.