The correct answer is B) eliminate the individual circuits one by one until the ground detecting system no longer indicates any grounds. When multiple grounds have developed and are initially indicated as a single ground by the ground-detecting system, the first step is to systematically eliminate the individual circuits one by one until the ground-detecting system no longer indicates any grounds. This allows you to isolate the specific circuit(s) where the ground(s) are located. Checking each circuit with a megohmmeter (option C) or examining the main bus bars (option D) may be subsequent steps, but the initial step is to eliminate the individual circuits to pinpoint the source of the multiple grounds. Options A and D are not directly relevant to the task of locating the grounds.