A bell mounted on the wall outside a classroom sounds. A student is positioned at point X, as shown in the overhead view. The classroom door is shut, and the student inside the room at X hears the bell. The door is then opened, and the sound from the bell heard by the student becomes louder. What causes the sound reaching the student to be louder?
- Adiffraction
- Bdispersion
- Creflection
- Drefraction