The correct options are
A S1 and S2 both cannot intersect.
B In the region between S1 and S2, the field is maximum where they are closed to each other.
D A line of force from S1 and S2 must be perpendicular to both.
As we know that two equipotential surfaces can not intersect each other and lines of force are always perpendicular to the equipotential surface.
When two equipotential lines close together, the slope will be steep. So, close equipotential surfaces indicate a maximum electric field.(E=−dVdx)
Ans: (A),(C),(D)