Answer is : (d) Allolactose and cAMP
The lac operon of E.coli contains genes involved in lactose metabolism.
Two regulators turn the operon ‘on’ and ‘off’ in response to lactose and glucose levels, the lac repressor and Catabolite Activator Protein (CAP). The lac repressor senses lactose through allolactose and stops acting as repressor. CAP activates transcription of operon sensing low glucose levels through cAMP.
