What is the first level of regulation of gene expression in eukaryotes?

The diagram below shows a diagrammatic sketch of the maturation of insulin. Select the correct set of names labeled $A, B, C$,and $D$.

Select two statements out of the four given statements $(i-iv)$ with respect to the $lac$ operon.
$(i)$ Glucose or galactose binds with the repressor and inactivates it.
$(ii)$ In the absence of lactose,the repressor binds with the operator.
$(iii)$ The $Z$-gene codes for permease.
$(iv)$ It was elucidated by Francois Jacob and Jacques Monod.

Match List-$I$ with List-$II$.

List-$I$	List-$II$
$A$. Gene $a$	$I$. $\beta$-galactosidase
$B$. Gene $y$	$II$. Transacetylase
$C$. Gene $i$	$III$. Permease
$D$. Gene $z$	$IV$. Repressor protein

Choose the correct answer from the options given below:

Assertion $(A):$ Regulation of $lac$ operon by repressor is referred to as negative regulation.
Reason $(R):$ Repressor protein binds to the operator region and prevents $\text{RNA}$ polymerase from transcribing the operon.

In the Operon concept,the regulator gene functions as: