Consider a (Two-Dimensional) Ring of Positive Charge, Uniformly Distributed

Multiple Choice

Consider a (two-dimensional) ring of positive charge, uniformly distributed. For a positively charged ring and a point charge Q near its geometric center, Q undergoes one-dimensional SHM for this single conjunction of cases:

A) Q negative: motion in axial direction and motion in plane of ring.
B) Q positive: motion in axial direction and motion in plane of ring.
C) Q negative: motion in axial direction and Q positive, motion in plane of ring.
D) Q positive: motion in axial direction and Q negative, motion in plane of ring.