An average nuclear reactor generates 1.2 MW of electricity daily. At least, how much mass is lost per day to generate this amount of energy? 

• A. 4.8x10^-11 g/day
• B. 4.3x10⁶ g/day
• C. 1.0x10¹¹ g/day
• D. 1.2x10^-6 g/day

Answer: (D)