What is the difference of the greatest \[7-\]digit number and the smallest \[5\] digit number?

• A.  \[9,\,\,98,\,\,999\]          
• B.                     \[99,\,\,89,\,\,999\]                    
• C.                     \[99,\,\,899\]                            
• D.                     \[9,\,\,98,\,\,099\]