The steps below identify the part of the process to become a U. S. citizen, the naturalization process. Use the steps below to answer the following question. 1. Be a legal resident in the U. S. for at least 5 years. 2. Complete an application 3. ? 4. Take the Oath of Allegiance What is missing in the process above? A: Register for Selective Service System B: Interview and pass civics test C: Complete a background check D: Receive an appointment letter