The correct answer is C) The specific gravity reading is lowered when the electrolyte temperature has increased. This is correct because as the temperature of the battery electrolyte increases, the density of the electrolyte decreases, resulting in a lower specific gravity reading. The specific gravity of the electrolyte is inversely proportional to the temperature - as the temperature rises, the specific gravity decreases. The other options are incorrect: A) is false because temperature does affect the specific gravity, B) is incorrect because the most accurate reading is obtained when the electrolyte has reached a stable temperature, and D) is incorrect because the electrolyte becomes less dense when it is heated, not cooled.