The correct answer is true.
It is true that Mississippian cultures most likely disappeared to disease, war, or migration.
Mississippian cultures lived in the regions of the Oklahoma, Ohio, and Mississippi valley. They were a prosper culture that lived from agriculture. They grew crops such as corn, beans, and squash in their fertile lands. But European conquerors such as Hernando de Soto and his men brought diseases unknown to the Native American Indians and they almost disappeared. Among other diseases they brought were smallpox, chickenpox, influenza, and malaria.