Beyond his role as a judge, what unique action did Ehud perform that demonstrated both courage and cunning in delivering Israel from Moabite oppression?

A He rallied the Israelite army in a massive frontal assault. B He negotiated a peace treaty with King Eglon through diplomacy. C He crafted a double-edged sword and assassinated King Eglon under the guise of a tribute offering. D He used a secret code to communicate with Israelite spies within Moab.