Archaeological Investigation of the Battlefield at Little Bighorn Was Able

Archaeological investigation of the battlefield at Little Bighorn was able to determine combatant positions and movements. How was this accomplished?

A) Intensive excavations of graves marked by grave markers that determined the position of American soldiers and Indian warriors where they fell in combat.
B) Extensive horizontal excavations that recovered numerous skeletal remains and artifacts of the battle, such as shell casings.
C) Survey with metal detectors that located cartridges and bullets, the positions of which were then carefully mapped.
D) All of the answers are correct.