Correct Answer : Option (A) :   Leading

Explanation :

First, we need to understand the term "Voltage regulation" in brief:

Voltage Regulation:

When the secondary terminal of the transformer carried the full load, and the secondary voltage varies even though the primary supply voltage is held constant at rated value.

% Voltage Regulation = [ V₂(N_L) - V₂ (F_L)] *100 /[V₂(N_L)]

If the rated voltage is applied to the primary winding of the transformer, the secondary voltage changes with the load current and power factor, even the primary voltage is kept constant. These changes in voltage of windings are known as voltage regulation.

Voltage regulation depends on the voltage drop in the transformer's impedance, load current and load power factor.