The bacterium, E. coli prefer to consume glucose. If, however, there is no glucose present, they will utilize lactose as an energy source. Which of the following is the regulatory mechanism occurring when there is no glucose, but there is lactose

Lactose is more likely to be utilised by E. Coli than Arabinose because Lactose will yield more energy (ATP) and lactose breakdown will give glucose and galactose and these will enter into the glycolytic pathways to pyruvate for ATP generation until Arabinose which will undergo Pentose phosphate pathway and this does not produce enough energy.