What was reason why the discovery of King Tutankhamen's tomb so important?

ANo Egyptian tombs had been discovered until archaeologists found Tut's tomb.

BPrevious excavations of other pharaoh's tombs had yielded no information about the ancient Egyptians.

CIt was the first royal Egyptian tomb that archaeologists discovered intact and in excellent condition.

DIt proved that King Tutankhamen was the greatest pharaoh of ancient Egypt.