How many $NADH + H^+$ molecules are produced during the process of glycolysis?

$A-$ During glycolysis,$2$ $ATP$ and $2$ $NADH_2$ are formed.
$R-$ $2$ $ATP + 2$ $FADH_2 + 4$ $NADH_2$ are produced during glycolysis.

Select the correct sequence of reactions in glycolysis:
$(a)$ $3$-phosphoglyceraldehyde $\rightarrow$ $1,3$-biphosphoglycerate
$(b)$ $3$-phosphoglyceric acid $\rightarrow$ $2$-phosphoglycerate
$(c)$ $1,3$-biphosphoglyceric acid $\rightarrow$ $3$-phosphoglyceric acid
$(d)$ Splitting of $1,6$-fructose biphosphate to dihydroxyacetone phosphate and $3$-phosphoglyceraldehyde

Which process does the following equation represent?
$C_6H_{12}O_6 + 2NAD^+ + 2ADP + 2\Pi \longrightarrow 2CH_3COCOOH + 2NADH + 2H^+ + 2ATP$

Choose the correct option:
$(1)$ Glucose and fructose are phosphorylated by the enzyme transferase/hexokinase to form glucose $6$-phosphate.
$(2)$ In fermentation,yeast converts glucose into ethanol under aerobic/anaerobic conditions.

Harden and Young's ester is formed during glycolysis from