Sphere R, made of metal, hangs from an insulating thread. Sphere S is moved near sphere R. Sphere S carries a negative charge and is fixed to a plastic stand. The diagram depicts the spheres when they are near one another. Which charged state of R explains the behaviour shown in the diagram?
- Anegative only
- Bpositive only
- Cnegative or uncharged
- Dpositive or uncharged