Which of the following, if true, most weakens the argument given? A. The present high cost of acoustic-sensor-based alarm systems will decline if their use becomes widespread. B. When fully ignited, many materials used in housing construction give off sounds that are audible even from several hundred yards away. C. Many fires begin in cushions or in mattresses, producing large amounts of smoke without giving off any sounds. D. Two or more acoustic-sensor-based alarms would be needed to provide adequate protection in some larger houses. E. Smoke detectors have been responsible for saving many lives since their use became widespread.