Prior to using an analog type ohmmeter, the leads are purposely shorted together. Which of the following actions should be taken if, when adjusting to 'zero' ohms, the indicating needle can not be returned to 'zero' on the scale? A. The lead clips should be replaced. B. The batteries should be replaced. C. The test reading should be added to each final reading. D. The test reading should be subtracted from each final reading.