Answer:
Option (a).
Explanation:
Enzymes are bio catalyst that can increases the rate of biochemical reaction. Enzymes are highly pH and temperature specific. They works at optimum temperature and pH.
Excess pH and temperature can alters the enzyme structure and may result in its denaturation. Preservation of food by freezing doesnot alters the enzyme structure. Freezing only alters the enzyme activity and does not cause enzyme denaturation.
Thus, the correct answer is option (a).
