A \[2-\]litre bottle is half-filled with water. How much more water must be added to fill up the bottle completely?

• A. \[\frac{1}{2}c{{m}^{3}}\]                   
• B.           \[100\,\,c{{m}^{3}}\]              
• C.           \[500\,\,c{{m}^{3}}\]              
• D.           \[1000\,\,c{{m}^{3}}\]