What must a bicycle contain when used at night?

• A headlight visible from at least 500 feet ahead and a red tail light visible from at least 300 feet behind.
  Explanation:

  "A bicycle used at night must have a headlight visible from at least 500 feet (150 m) ahead and a red tail light visible from at least 300 feet (90 m) behind. One of these lights must be visible from at least 200 feet (60 m) away on each side."
• A headlight visible from at least 200 feet ahead and a red tail light visible from at least 100 feet behind.
• A headlight visible from at least 300 feet ahead and a red tail light visible from at least 200 feet behind.
• A headlight visible from at least 100 feet ahead and a red tail light visible from at least 50 feet behind.