Step 1: Consider a small charge element $dq$ on the ring at angle $\theta$.

Step 2: Its field at the centre has magnitude $dE = \dfrac{k\,dq}{R^2}$, directed radially.

Step 3: For every element, there is a diametrically opposite element producing an equal and opposite field component.

Step 4: By symmetry, all field contributions cancel in pairs.

Answer: Net electric field at the centre $= 0$ (Option B).