A coil of wire of cross-section \[0.50\text{ }m{{m}^{2}}\] weighs 75g in air and 65g in water. The length of the coil in cm is

• A. \[\frac{{{10}^{2}}}{50}\]              
• B. \[\frac{{{10}^{2}}}{0.50}\]           
• C. \[\frac{{{10}^{5}}}{50}\]  
• D.        \[\frac{{{10}^{5}}}{0.0050}\]