Which of the following is not correct?

Which of the following processes is $NOT$ involved in the extraction of metal from cassiterite $(SnO_2)$ ore?

The advantage$(s)$ of using $O_2$ rather than air in the steel industry is(are):
$(I)$ There is a faster conversion,so a given plant can produce more steel in a day.
$(II)$ Larger quantities can be handled.
$(III)$ It gives a purer product,and the surface is free from nitrides.

Bell metal is an alloy of

Given below are two statements:
Statement $I$: During electrolytic refining,the pure metal is made to act as anode and its impure metallic form is used as cathode.
Statement $II$: During the Hall-Heroult electrolysis process,purified $Al_2O_3$ is mixed with $Na_3AlF_6$ to lower the melting point of the mixture.
In the light of the above statements,choose the most appropriate answer from the options given below:

Give the correct order of initials $T$ or $F$ for following statements. Use $T$ if statement is true and $F$ if it is false.
$(i)$ In Goldschmidt thermite process,aluminium acts as a reducing agent.
$(ii)$ $Mg$ is extracted by electrolysis of aqueous solution of $MgCl_2$.
$(iii)$ Extraction of $Pb$ is possible by carbon reduction method.
$(iv)$ Red Bauxite is purified by Serpeck's process.