There is a current of 20 amperes in a copper wire of \[{{10}^{-6}}\] square metre area of cross-section. If the number of free electrons per cubic metre is \[{{10}^{29}}\], then the drift velocity is

• A.                    \[125\times {{10}^{-3}}m/sec\]
• B.                                      \[12.5\times {{10}^{-3}}m/sec\]
• C.                    \[1.25\times {{10}^{-3}}m/sec\]                              
• D.            \[1.25\times {{10}^{-4}}m/sec\]