The temperature of inversion of a thermocouple is $620^{\circ}C$ and the neutral temperature is $300^{\circ}C$. What is the temperature of cold junction :

Question

( A ) $20^{\circ}C$
( B ) $40^{\circ}C$
( C ) $–20^{\circ}C$
( D ) $320^{\circ}C$