In the late 7th century, the Native American population dropped drastically due to a <span>contagious disease.
</span><span> contagious </span>diseases can transmit from person to another easily.
The Red Scare or communism was the <span> political system that emerged directly from world war 1.</span>
Robespierre led the C. reign of terror
The answer is B, although C and D could be true they are not mentioned in the passage