Final answer:
Alsace and Lorraine were resolved in the peace conference through the Treaty of Versailles, which returned them to France and imposed penalties on Germany.
Step-by-step explanation:
During the peace conference, Alsace and Lorraine were resolved through the Treaty of Versailles. This treaty imposed harsh penalties on Germany, including returning Alsace and Lorraine to France and imposing a massive indemnity on Germany. Germany also had to accept the 'war guilt clause,' taking full responsibility for starting the war. As a result, bitterness and reprisals followed, and few believed that another world war would occur in the future.