A cell has an open circuit voltage V₁ and a closed circuit voltage V₂ when a current is flowing through it. Therefore, the internal resistance of the cell is

• A.\(\frac{V_2}{I}\)
• B.\(\frac{V_1}{I}\)
• C.\(\frac{(V_1 + V_2)}{I}\)
• D.\(\frac{(V_1 - V_2)}{I}\)
• E.\(\frac{(V_2 - V_1)}{I}\)