Which of the following are opening/closing remarks?

• Группы
  • Opening remarks:
  • Closing remarks:
• Варианты
  • How are you?
  • Sorry, I didn't write earlier but I was busy with schoolwork.
  • I look forward to hearing from you.
  • Write back soon.
  • Hope you are OK.
  • That's all for now.
  • Best wishes.
  • It's always nice to hear from you.
  • How's it going?
  • I have to go now.