Which one of the following correctly defines 1 K, as per the internationally accepted definition of temperature scale?

• A. 1/100th of the difference between normal boiling point and normal freezing point of water
• B. 1/273.15th of the normal freezing point of water
• C. 100 times the difference between the triple point of water and the normal freezing point of water
• D. 1/273.16th of the triple point of water