The correct answer is C) load testing each cell with a voltmeter. The best way to locate a weak or dead cell in an alkaline storage battery is to load test each cell individually with a voltmeter. This allows you to measure the voltage under load, which will reveal any cells that are not holding a charge properly. The other options, while potentially useful for other battery maintenance tasks, are not as effective for directly identifying weak or dead cells. Visually inspecting the electrolyte level (A) can indicate issues, but does not provide a direct measurement of the cell's condition. Measuring the electrolyte temperature (B) is not as relevant for alkaline batteries. Checking the specific gravity (D) is more commonly used for lead-acid batteries, not alkaline types. Load testing each cell (C) is the most reliable method to pinpoint any problem cells in an alkaline storage battery.