Question

In lac operon, the regulator gene codes for
(1) Aporepressor
(2) Corepressor
(3) Inactive repressor
(4) Active repressor​

Answer 1

4) $\bf{Active\: Repressor}$

Explanation:

Regulator gene(represented with "i") would always be regulating an active Repressor, whereas the Repressor becomes inactive(during the presence of Lactose) when it combines with Inducer.

So basically it's the presence of Inducer which ensures Repressor to be active or inactive.

#Note

Don't get confused with Inducer & Inhibitor

• Inhibitor is a gene(i.e a regulatory gene)
• Inducer is a protein (which comprises Allosteric sites i.e a binding site)

Hope it helps you! ^_^