Please choose the correct answer to the question: A person in a dark room looking through a window can clearly see a person outside in the daylight. But a person outside cannot see the person inside. Why does this happen?

Answer1: There is not enough light being reflected off the person in the room. Answer2: Light rays cannot pass through a window twice. Answer3: Outside light does not pass through windows. Answer4: Sunlight is not as intense as other sources of light.

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