Please choose the correct answer to the question: Which BEST explains why green marine algae are most often restricted to the top 100 meters of the ocean?

Answer1: They have no roots to anchor them to the ocean floor. Answer2: They can live only where there is light. Answer3: The pressure is too great for them to survive below 100 meters. Answer4: If the algae lived below 100 meters they would be eaten by animals.

Answer format: answer1/answer2/answer3/answer4