Jacob and Monod were intellectually primed to draw the conclusions they did concerning regulation of the lac operon. In part, this was due to their fascination with mechanisms of enzyme regulation. They knew that the activity of some enzymes is regulated when their reaction product binds to the enzyme, changing its shape and therefore its activity. This knowledge allowed them to easily make the intellectual leap to propose .A) the existence of the CAP binding siteB) allosteric regulation of the repressorC) positive regulation of the lac operonD) the existence of the operatorE) co-transcribed and co-regulated genes of bacterial operons

Jacob and Monod were intellectually primed to draw the conclusions they did concerning regulation of the lac operon. In part, this was due to their fascination with mechanisms of enzyme regulation. They knew that the activity of some enzymes is regulated when their reaction product binds to the enzyme, changing its shape and therefore its activity. This knowledge allowed them to easily make the intellectual leap to propose B) allosteric regulation of the repressor

Explanation:

When we talk about the mechanisms of enzyme regulation, we refer to allosteric regulation of the repressor. The Allosteric control of transcriptional regulatory proteins allows organisms to react to changes in environmental and metabolic conditions. Also, it is s a thermodynamic phenomenon. When it binds one molecule, the affinity with which a protein binds to a second molecule is altered.

i believe the answer would be b. hope it : )