Which of the following statements regarding enzymes is true?

Answer:
B
Explanation:
Enzymes are widely known to speed up reactions. All of the other answer choices are incorrect.
Answer:
1.b:Enzymes increase the rate of reaction.
2.b:lowering the energy of activation of a reaction.
Explanation:
1.Enzyme : Enzymes are biological catalyst .It is defined as proteins binds to a molecule and increase the rate of reaction.It does not change in the reaction only it increases the rate of reaction.
Enzyme does not decrease the free energy change of a reaction.Enzymes do not change in the concentration of substrate and do not prevent the changes in substrate concentration.It only increase the rate of reaction .
Therefore, option b is true.
b:Enzymes increase the rate of reaction.
2.Activation energy:It is defined that minimum energy which is required for molecules to start the reaction .
When an enzyme catalyze a reaction then the activation energy of energy of molecules decreases and speed up the reaction.
Hence, option b is true.
Answer :b:lowering the energy of activation of a reaction.