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

  Options: 
 A. room is totally dark.
 B. light source is ultraviolet.
 C. beam of light does not travel toward the students.
 D. room walls are shielded with insulating material.
Answer: C