Which of the following water solutions is an electrolyte?

• A. NaCl(aq)
• B. CH_3OH(aq)
• C. CCl_4(aq)
• D. C_6H_{12}O_6(aq)

Answer: (A)

Verified step by step guidance

1. Understand what an electrolyte is: an electrolyte is a substance that, when dissolved in water, produces ions and thus conducts electricity.
2. Identify which substances dissociate into ions in aqueous solution. Ionic compounds like NaCl dissociate into Na\^{+} and Cl\^{-} ions.
3. Recognize that molecular compounds like CH_3OH (methanol), CCl_4 (carbon tetrachloride), and C_6H_{12}O_6 (glucose) do not ionize significantly in water; they mostly remain as neutral molecules.
4. Conclude that only NaCl(aq) produces ions in solution and therefore acts as an electrolyte.
5. Summarize that the key to identifying an electrolyte is to check if the compound dissociates into ions in water, enabling electrical conductivity.