Some Scientists Think That Yellowstone Could Cause a Future Disaster

Some scientists think that Yellowstone could cause a future disaster because:

A) the area is part of a caldera
B) scientists think that magma is still present at depth
C) past eruptions from Yellowstone carried ash over a huge area of western North America
D) land near Yellowstone is uplifting in some places and subsiding in others
E) all of these