Electrolytes are substances that dissociate into ions when dissolved in water, allowing them to conduct electricity.
In the options provided:
A. NH4Cl and KCl - Both of these compounds are ionic salts that dissociate into ions in solution, making them electrolytes. B. KCl and CH3OH - KCl is an electrolyte, but CH3OH (methanol) is not, as it does not dissociate into ions. C. NH4Cl and C6H12O6 - NH4Cl is an electrolyte, but C6H12O6 (glucose) is not, as it does not dissociate into ions. D. C6H12O6 and CH3OH - Neither of these compounds are electrolytes, as neither dissociates into ions in solution.
Therefore, the correct answer is A. NH4Cl and KCl.