Final answer:
The correct response is that the system experienced a temporary disturbance and then readjusted to a new steady state after the concentration change.
Step-by-step explanation:
The question pertains to the effect of a sudden concentration change on a chemical system that was initially in a steady state. When the feed concentration is abruptly increased from 0.25 mol/L to 5 mol/L at t=0, the correct answer is c) The system experienced a temporary disturbance before readjusting to a new steady state. This phenomenon occurs due to Le Châtelier's principle, which states that a disturbance in the concentration of reactants or products will result in the system changing to re-establish equilibrium. In this case, the system will adjust the concentrations of reactants and products as per the new conditions until a new equilibrium is reached.