For a transistor,in a common emitter arrangement,the alternating current gain $\beta$ is given by

• A
  $\beta = \left( \frac{\Delta I_C}{\Delta I_B} \right)_{V_{CE}}$
• B
  $\beta = \left( \frac{\Delta I_B}{\Delta I_C} \right)_{V_{CE}}$
• C
  $\beta = \left( \frac{\Delta I_C}{\Delta I_E} \right)_{V_{CE}}$
• D
  $\beta = \left( \frac{\Delta I_E}{\Delta I_C} \right)_{V_{CE}}$