Net Charge on Neutral Conducting Sphere Near Point Charge

To determine the net charge on the conducting sphere, we use the principle of conservation of electric charge:

1. Initial State:
   The conducting sphere is initially neutral, which means the total initial charge on the sphere is zero:
   $Q_{\text{net, initial}} = 0$

2. Electrostatic Induction:
   When a positive point charge $+q$ is placed outside the sphere, an external electric field is established. Since the sphere is a conductor, free electrons inside it migrate toward the region of the sphere's surface closest to the external positive charge due to electrostatic attraction.

   This leads to a redistribution of charges:

   • A negative induced surface charge ($q_{\text{ind}} < 0$) appears on the side facing the external point charge.
   • An equal magnitude of positive induced surface charge ($-q_{\text{ind}} > 0$) appears on the opposite side of the sphere.

3. Net Charge Conservation:
   The sphere is electrically isolated and neither connected to ground nor to any other charge reservoir. No electrons or ions are transferred to or from the sphere. Therefore, the net charge on the sphere remains conserved:
   $Q_{\text{net}} = q_{\text{ind}} + (-q_{\text{ind}}) = 0$

Thus, while the surface charge distribution becomes non-uniform due to induction, the net charge on the sphere remains zero.

Therefore, the correct option is D.