The answer is A. And here's why.
First the lactase must attach itself to the lactose molecule, upon doing that it hydrolyges it into glucose and galactose.
I hope this helps.
The correct option is D.
Wind has some advantages which makes it suitable as a source of energy but it also possesses some disadvantages which reduces its potentials as a viable source of energy. For instance, large expanse of land will be needed to construct wind farms and this may not be feasible especially in populated areas. Another disadvantage is that electricity production will be depended on the availability of wind, when there is no wind, there will be no electricity.