Which of the following patterns of electric field lines is $NOT$ possible for an electrostatic field due to static charges?

$A$ cube of side $b$ has a charge $q$ at each of its vertices. The electric field due to this charge distribution at the centre of this cube will be

In the following four situations,charged particles are at an equal distance from the origin. Arrange them in order of the magnitude of the net electric field at the origin,starting from the greatest.

Two spheres of electric charges $+2 \ nC$ and $-8 \ nC$ are placed at a distance '$d$' apart. If they are allowed to touch each other,what is the new distance between them to get a repulsive force of the same magnitude as before?

Four charges are arranged at the corners of a square $ABCD$,as shown. The force on a $+ve$ charge kept at the centre of the square is

The following figures show regular hexagons with charges placed at their vertices. In which of the following cases is the electric field at the center zero?