A) ( \alpha = \frac{N_A}{N_B})B) ( \alpha = \frac{N_P}{N_D})C) ( \alpha = \frac{N_0}{N_B})D) ( \alpha = \frac{N_D}{N_P})
A) ( \alpha = \frac{N_A}{N_B})
B) ( \alpha = \frac{N_P}{N_D})
C) ( \alpha = \frac{N_0}{N_B})
D) ( \alpha = \frac{N_D}{N_P})