an increased loudness of sound a reflection of sound an increased frequency of sound a refraction of sound
I am hesitating between 4 options to answer the following question, which option should I choose?
Question: A student in an empty classroom shouts, "Hello!" Which best explains what the student hears after the shout?
Possibilities:
- an increased loudness of sound
- a reflection of sound
- an increased frequency of sound
- a refraction of sound

a reflection of sound