The efficiency of Carnot's engine operating between reservoirs, maintained at temperatures \[{{27}^{o}}C\] and \[-{{123}^{o}}C,\] is [DPMT 2002, 03; BVP 2004]

• A.            50%                                          
• B.            24%
• C.            0.75%                                      
• D.            0.4%