In the prophecy concerning the 'Valley of Dry Bones' in Ezekiel 37, what does God promise to do for the house of Israel, symbolizing their spiritual restoration?

A To establish a new temple in Jerusalem, surpassing Solomon's in glory. B To physically resurrect the dead from their graves, demonstrating His power over death. C To bring them back to their land, cleanse them from their idolatry, and give them a new heart and spirit. D To send a powerful military leader to conquer their enemies and establish a global empire.