Which statement describes MD5 authentication for neighbor authentication?

Which statement describes MD5 authentication for neighbor authentication?

• All passwords are sent in clear text when neighbors first learn about each other.
• Only the initiating router sends its password using encrypted text when it first discovers a new router.
• All routers send their password using encrypted text only when they first learn of each other.
• All routers send their password using encrypted text each time they exchange update packets.

Exam with this question: CCNA Discovery 4: DCompNtwk Chapter 6 Exam