The temperature of an isolated black body falls from $$T_1$$ to $$T_2$$ in time t. Then $$t = Cx$$ where x is

A

$$\left(\frac{1}{T_2} - \frac{1}{T_1}\right)$$

B

$$\left(\frac{1}{T_2^2} - \frac{1}{T_1^2}\right)$$

C

$$\left(\frac{1}{T_2^3} - \frac{1}{T_1^3}\right)$$

D

$$\left(\frac{1}{T_2^4} - \frac{1}{T_1^4}\right)$$