Which stage is common to lactic acid fermentation,alcoholic fermentation,and aerobic respiration?

In which of the following processes does the isomerization step take place?

Glycolysis:
$I$. Causes partial oxidation of glucose (one molecule) to form $2$ molecules of pyruvic acid and $2$ $ATP$ as net gain.
$II$. Takes place in all living cells.
$III$. Uses $2$ $ATP$ at two steps.
$IV$. Scheme was given by Gustav Embden,Otto Meyerhof,and $J$. Parnas.
Choose the correct option containing appropriate statements from the above.

In which of the following reactions of glycolysis, oxidation takes place?

The conversion of fructose-$6$-phosphate to fructose-$1,6$-bisphosphate during respiration requires which of the following enzymes?

Which enzyme is active only in the presence of $Mg^{2+}$, $Mn^{2+}$, or $Zn^{2+}$?