Concept:Darius recognised God's supreme power when Daniel remained faithful and steadfast even in the face of death.
Explanation:King Darius issued an edict forbidding prayer to any god except the king for thirty days.
Daniel refused to disobey God and continued praying to Him as he always did.
For this act of loyalty, Daniel was thrown into a den of lions.
God sent His angel to shut the mouths of the lions, and Daniel was completely unharmed.
Darius then acknowledged that Daniel's God is the living God, whose kingdom shall never be destroyed.
Therefore, it was Daniel's faithfulness and steadfastness that convinced Darius of God's power.
Answer:C. faithfulness and steadfastness