(i) Both assertion and reason are true and the reason is the correct explanation of assertion.

Both the statements are true and the reason is also true. Conductivity of all electrolytes (both, weak and strong electrolytes) decreases on dilution as number of ions per unit volume decreases with dilution. Thus, the amount of current carried by the ions per unit volume also decreases.

Hence, Conductivity of all electrolytes decreases on dilution because with dilution, the number of ions per unit volume decreases.