Which of the following is the correct match?

The zone refining of metal is based on the principle of

Which method of refining nickel is represented by the following equation?
$Ni$ (impure) $+ 4CO$ $\xrightarrow{320 \ K} Ni(CO)_4$ $\xrightarrow{420 \ K} Ni$ (pure) $+ 4CO$

When an impurity in a metal has greater affinity for oxygen and is more easily oxidised than the metal itself,the metal is refined by:

The formation of $Ni(CO)_4$ and its subsequent decomposition into $Ni$ and $CO$ forms the basis of the Mond process.
$Ni + 4CO$ $\xrightarrow{T_1} Ni(CO)_4$ $\xrightarrow{T_2} Ni + 4CO$
What are the values of $T_1$ and $T_2$?

What is annealing?