Which of the following statements is correct about cryosphere?

• A.  These are such parts of earth's system where temperature goes down below \[{{0}^{o}}C\] at least one year                                     
• B.  The largest component of Cryosphere is the belt of Greenland and Antarctica.             
• C.  Marine snow, ice shelf, frozen land and ice caps the components of Cryosphere              
• D.  All the above