The correct answer is: A. Zero.
A voltmeter is an instrument used to measure the voltage (electrical potential difference) between two points in an electric circuit.
It is a type of ammeter, an instrument used to measure electric current.A voltmeter should have zero resistance so that it does not affect the circuit it is measuring. If the voltmeter had any resistance, it would introduce a voltage drop in the circuit, which would affect the measurement.
Option B is incorrect because a voltmeter with very high resistance would not be able to measure
the voltage accurately. The voltage drop across the voltmeter would be too small to be measured.Option C is incorrect because a voltmeter with very low resistance would draw too much current from the circuit. This could damage the voltmeter or the circuit.
Option D is incorrect because it does not provide a correct answer.