If $\theta_i$ is the inversion temperature, $\theta_n$ is the neutral temperature, $\theta_c$ is the temperature of the cold junction then :

Question

( A ) $\theta_i + \theta_c = \theta_n$
( B ) $\theta_c - \theta_i =2 \theta_n$
( C ) $\frac{\theta_i+\theta_c}{2} = \theta_n$
( D ) $\theta_i - \theta_c =2 \theta_n$