3. Which of the following battles gave Kassa Hailu a lesson to modernize his army? A. Debarki B. Deresege C. Ayshal mindown and the British was D.Wad kaltabu (D) Gur Amba . Gorgora Bichlgn Ayshal-Delesge

The correct answer is A. Debarki.<br /><br />The Battle of Debarki was a significant conflict in which Kassa Hailu, the Emperor of Ethiopia, faced a defeat. This defeat served as a lesson for Kassa Hailu to modernize his army and improve his military strategies.