$A\;\;;\;\;B\;\;;\;\;C$
| List $-I$ | List $-II$ |
| $a$ In lac operon $i$ gene codes for | $i$ transacetylase |
| $b$ In lac operon $z$ gene codes for | $ii$ permease |
| $c$ In lac operon $y$ gene codes for | $iii$ $\beta$ - galactosidase |
| $d$ In lac operon $a$ gene codes for | $iv$ Repressor |
Choose the correct answer from the options given below :