Which of the following statement is true regarding mufflers?

• Mufflers are required only if the vehicle is producing excessive noise
• Vehicles must have a muffler in good working order to eliminate noise
  Explanation:

  "Every vehicle must be equipped with a muffler in good working order to eliminate excessive or unusual noise. The use of muffler cutouts, bypasses, or similar devices is prohibited."
• Mufflers are optional; vehicles can operate without them
• Mufflers are necessary only during specific hours of the day