Explanation: To accurately assess a dry cell's condition, testing under load is crucial. A failing dry cell often exhibits a normal "no-load" voltage due to its internal resistance not dropping voltage without current flow. However, once a load is applied (even a small one, like a resistor or the device it powers), the internal resistance causes a significant voltage drop, revealing its true depleted state. Therefore, it *must be tested under normal load conditions* to get a realistic reading (A). Furthermore, the voltage measurement itself can *be taken by any conventional voltmeter* (C). Standard analog or digital voltmeters are designed to measure DC voltage and are perfectly suitable for checking a dry cell's output. Since both statements A and C are correct, the best answer is D. While you *can* test a dry cell under no load (B), this often provides a misleadingly high voltage reading for a dying battery, making it an unreliable method for determining its practical usefulness.