You are calibrating a multimeter using internal batteries to supply power for resistance measurements. However, you are unable to adjust the pointer to 'zero' using the adjustment knob. Therefore, you should _____________. A. replace the batteries in the instrument B. measure resistance by dividing the voltmeter indication by the ammeter indication C. set the pointer using a bridge D. change scales to the R X 100 scale and adjust using the 'zero ohms' adjusting knob