Final answer:
The tank battalion that broke through the German lines during the Battle of the Bulge was the 4th Armored Division, also known as the "Phantom Division."
Step-by-step explanation:
The tank battalion that broke through the German lines during the Battle of the Bulge was the 4th Armored Division, also known as the "Phantom Division." Led by General George S. Patton, the 4th Armored Division launched a counterattack that relieved the besieged city of Bastogne and pushed the German forces back.