The correct option is
A 1.7×10−2QThe arrangement can be seen as a two dipole system if we focus on equal and opposite charges. (as we know equal and opposite charges separated by fixed distance forms a dipole).
Each dipole has a charge +Q and separation of 0.01 m so ∣∣∣→P∣∣∣=0.01Q as the angle between them is
60∘ the net dipole moment is
∣∣∣−−→Pnet∣∣∣=
√(0.01Q)2+(0.01Q)2+2×0.01Q×0.01Q×cos60∘
=0.01×√3Q.
=1.7×10−2Q
As we can see from symmetry it will be directed in the positive y direction (mid way between the two vectors)