The form of iron having the highest carbon content is

Read the following statements :
$(I)$ $Al$ has greater affinity than that of $Cr$ for oxygen
$(II)$ $Al$ can be used for reduction of $Fe_2O_3$
$(III)$ Carbon is used for reduction of $PbO$
$(IV)$ $SnO_2$ can be reduced by carbon
Choose the correct set of statement$(s)$:

Identify the reaction,which is not related to the extraction of copper.

Identify the correct statement from the following:

Which of the following is not correct?

Which of the following processes is not used for the extraction of spelter from zinc blende?