What is the overall efficiency of a fuel cell? (E=Delivered voltage, I=current delivered for a period of time T)

• A. \(\frac{(EIT)}{∆H} \)
• B. \(\frac{(ET)}{∆HI} \)
• C. \(1-(\frac{(EIT)}{∆H}) \)
• D. \(\frac{∆H}{EIT} \)