Which miracle performed by Elisha is most debated regarding its literal interpretation due to its seemingly improbable nature?

A Causing an ax head to float (2 Kings 6:6) B Purifying the water supply of Jericho (2 Kings 2:21-22) C Raising the Shunammite woman's son (2 Kings 4:32-37) D Cursing the youths who mocked him, resulting in their deaths by bears (2 Kings 2:23-25)