The product of 'i' gene in lac operon binds to

The correct option is A Operator gene
The lac operon is an operon responsible for transport and metabolism of lactose in Escherichia coli and other bacteria. Gene "i" is the regulator gene that regulates the expression of structural genes by its protein product that are mostly transcription factors. These transcription factors bind to the operator region which is located just upstream the biding site of the RNA polymerase and hence prevent the binding and transcription. Operator is a DNA sequence present between the promoter region and the first coding gene. This operator region serves as repressor protein binding site. The gene that codes for any RNA / protein product which do not serve as regulatory protein are known as structural genes. Correct option is B.