$A$ hot and a cold body are kept in a vacuum,separated from each other. Which of the following causes a decrease in the temperature of the hot body?

$A$ body is in thermal equilibrium with its surroundings. This is because .....

The temperature of the sun is measured with:

The rate of emission of a body doubles when its temperature is increased by $10^{\circ}C$. If the temperature of the body is increased from $10^{\circ}C$ to $100^{\circ}C$,the rate of emission increases by a factor of:

Two identical objects $A$ and $B$ are at temperatures $T_A$ and $T_B$ respectively. Both objects are placed in a room with perfectly absorbing walls maintained at temperature $T$ $(T_A > T > T_B)$. The objects $A$ and $B$ attain temperature $T$ eventually. Which one of the following is the correct statement?

''$A$ perfect black body is black in colour.'' Is this statement true or false?