Final answer:
The correct answer is Option A. Zero, relying on the principle that conductors redistribute charges to nullify internal electric fields, which is also affirmed by Gauss's Law in electrostatics.
Step-by-step explanation:
The question deals with the effects of an external electric charge on a conducting body. In electrostatics, conductors have the property of redistributing their charges to negate any external electrical fields within their volume.
When a charge 'q' is placed outside a conducting body, the body will induce an equal but opposite charge on its inner surface to ensure that the electric field inside the conductor and, in particular, at any point O within the conductor, is zero. This is in line with the electrostatic shielding effect of conductors and its response to external electric fields, which is guaranteed by Gauss's Law.
Given this understanding of how conductors interact with electric fields, the electric field at point O due to induced charges on the conducting body would be zero. Therefore, the correct answer to this question is Option A. Zero.