In a Traditional Zoroastrian Funeral Ritual at a Tower of Silence

In a traditional Zoroastrian funeral ritual at a tower of silence, the bones of a dead person are swept into a large stone box in the central well in the tower to:

A) guard them until they are buried in the earth.
B) preserve them reverently until the resurrection.
C) preserve them for feeding later to the "four-eyed" dog.
D) protect them until they are offered to the sacred fire in the fire temple.