What is the full form of $FMN$?

Vitamins function as .........

In which one of the following enzymes is copper necessarily associated as an activator?

Which of the following enzymes are activated in the presence of $Mg^{++}$?
$(A)$ Pyruvate dehydrogenase
$(B)$ $DNA$ polymerase
$(C)$ Hexokinase
$(D)$ Rubisco
$(E)$ Catalase
$(F)$ $PEP$ carboxylase
$(G)$ Amylase
Options:
$(a)$ $B, C, D, E$
$(b)$ $A, F, C, D$
$(c)$ $G, F, B, E$
$(d)$ $A, F, C, B$

What is the cofactor of the most abundant enzyme in the biosphere?

If organic compounds are loosely bound to the apoenzyme,what are they called?