<em><u>The correct option is A) carbohydrate chain</u></em>
Explanation:
The carbohydrate chain present in the cell membrane helps determine the characteristics of the cell and it also helps to identify the chemical signals from outside the cell. Hence, option A is correct.
Other options, like option B, is not correct because the function of the cholesterol in the cell membrane is to prevent the fatty acids from sticking together. Option D is not correct because transport proteins help some molecules to move inside the cell.
I am pretty sure that the side of a mountain range that faces the wind often receives more<span> precipitation </span><span>than the downwind side of the same range.</span>