When approaching railroad crossings, what should you do to better hear audible signs or whistles?

• Roll your windows up to block out outside noise
• Turn your radio volume up to drown out external sounds
• Roll your windows down, turn your radio down, and listen carefully
  Explanation:

  "Audible signs or whistles may be difficult to hear when approaching railroad crossings. Roll your windows down, turn your radio down, and listen carefully."
• Ignore any audible signs or whistles