In Lac-operon, the gene product of LacA gene is

The correct option is Beta-galactoside transacetylase.

The lac operon (lactose operon) is a operon required for the transport and metabolism of lactose in Escherichia coli and many other enteric bacteria. It consists of three adjacent structural genes: lacZ, lacY, and lacA.

Each of these structural genes codes for a specific enzyme involved in lactose metabolism:
1. lacZ: Codes for β-galactosidase, which hydrolyzes lactose into glucose and galactose.
2. lacY: Codes for β-galactoside permease, which facilitates the entry of lactose into the bacterial cell.
3. lacA: Codes for β-galactoside transacetylase, which transfers an acetyl group from acetyl-CoA to β-galactosides.

Therefore, the gene product of the lacA gene is β-galactoside transacetylase (also referred to as beta-galactoside transacetylase).