How can drivers help themselves remain alert during long trips?

• By closing the windows to eliminate the sound of the wind
• By ignoring the hum of the engine
• By focusing on a single area of the roadway
• By engaging in conversation with other passengers and listening to lively radio programs
  Explanation:

  "Drivers can help themselves remain alert during long trips by engaging in conversation with other passengers and lively radio programs. However, they must pay attention to the traffic around them and potentially hazardous highway conditions."