Answer :
Final answer:
The correct way to say goodbye to a friend not seen for a long time is "¡Adiós!".
Explanation:
When saying goodbye to a friend whom you might not see for a long time, the correct option is ¡Adiós!. This term is commonly used to bid farewell for a longer duration. Other options like Hasta luego (See you later) or Hasta mañana (See you tomorrow) imply a shorter time frame.
Learn more about saying goodbye in different contexts here:
https://brainly.com/question/17168773