Please choose the correct answer to the question: Helena investigates how enzymes are important to body processes. How is the role of enzymes in biochemical activity best explained?

Answer1: Enzymes work at all pH levels. Answer2: Enzymes decrease the rate of metabolism. Answer3: Enzymes enable reactions to occur at lower temperatures. Answer4: Enzymes raise the activation energy needed for a reaction.

Answer format: answer1/answer2/answer3/answer4