Please choose the correct answer to the question: While conducting an investigation on refraction, a teacher uses a red laser pointer to show how a beam of light is affected as it passes through several glass objects. The teacher should make sure that the

Answer1: room is totally dark. Answer2: light source is ultraviolet. Answer3: beam of light does not travel toward the students. Answer4: room walls are shielded with insulating material.

Answer format: answer1/answer2/answer3/answer4
Answer: answer3