An uncharged metal sphere is suspended by an insulating thread. A positively charged insulating rod is brought close to the sphere, but does not touch it. Which of the following is/are true:

a.
Positive charge will accumulate on the surface of the sphere furthest from the rod.

b.
Electrons in the metal of which the sphere is comprised will be attracted by the net positive charge on the rod. This will give rise to an excess of negative charge on the surface of the sphere close to the rod.

c.
The net charge on the sphere will remain zero.

d.
All of the above.