What are the warning signs that indicate your drowsiness is serious enough to place you at risk while driving?

• You have difficulty keeping your eyes open
• You can’t remember details about the last few kilometers you have travelled
• Your mind keeps wandering and you can’t seem to concentrate
• All of the above
  Explanation:

  "Here are some important warning signs that your drowsiness is serious enough to place you at risk: (1) You have difficulty keeping your eyes open; (2) Your mind keeps wandering, and you can't seem to concentrate; (3) You can't remember details about the last few kilometers you have travelled."