In which of the following are monocistronic genes found?

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:

Select the two correct statements out of the four $(i-iv)$ statements given below about the lac operon.
$(i)$ Glucose or galactose may bind with the repressor and inactivate it.
$(ii)$ In the absence of lactose,the repressor binds with the operator region.
$(iii)$ The $z$-gene codes for permease.
$(iv)$ This was elucidated by Francois Jacob and Jacques Monod.
The correct statements are:

When glucose is the normal energy source in a bacterial cell,which gene transcribes a repressor mRNA?

When does $lac$ operon in $E. coli$ become "switched on"?

In the medium where $E$. coli was growing, lactose was added, which induced the lac operon. Then, why does the lac operon shut down some time after the addition of lactose in the medium?