Correct Answer - C::D
When there are various types of charges in a region, but the total charge is zero, the region can be supposed to contain a number of electric dipoles. Therefore, at points outside the region (may be anywhere w.r.t. electric dipoles) the dominant electric field `prop(1)/(r_(3))` for large r.
Further, as electric field is conservative, work done to move a charged particle along a closed path, away from the region will be zero.