In the 1930s, an Event Occurred at the Spiro Site

In the 1930s, an event occurred at the Spiro site that has hindered our ability to make reliable conclusions about the role of the town in relations between Mesoamerica and the Eastern Woodlands. What happened?

A) the site was improperly excavated and only poor documentation exists
B) the Pocola Mining Company looted the site and removed thousands of artifacts
C) the site was used for farming before it could be properly excavated destroying the context of most artifacts
D) a tornado interrupted excavations and destroyed most of the site documentation