Which benifit of ice on the surface of a lake is most helpful for fish
A: it shades the fish from the heating effects from the sun
B: it helps them stay cold
C: it prevents them from swimming in the winter
D: it insulates the fish from the cold air above

D. It insulates the fish from the cold air above.

Explanation:

Ice is less dense then water that's why float on surface of water. Ice on the lake act as a an Insulator.

an active site is a region that is present on an enzyme where the reactants or the substrate molecules we can say bind and experience a chemical reaction. the substrate is basically a reactant whose concentration is changing and that is converting into a product after binding at the active site of an enzyme