A student produces a sound at point $R$ close to a building. A second student at point $S$, standing around the corner of the building, can hear the sound. The building is a solid structure and there are no other structures in the vicinity. Which effect best explains why the student at point $S$ is able to hear the student at point $R$?
- Adiffraction
- Binterference
- Cpolarisation
- Dreflection