Step 1: Understanding the motion of the object.
The object under gravitational influence moves in a plane due to the central nature of the gravitational force. This is a well-established result from the conservation of angular momentum. The total energy being negative does not necessarily imply a circular orbit, and the orbit is parabolic if the total energy is zero. The area swept by the object is proportional to the time period, following Kepler's laws. Thus, the time period is \( 2mS/\ell \).
Step 2: Conclusion.
Thus, the correct answers are options (B), (C), and (D).