Answer
Choice B.
Work Step by Step
An ammeter is wired in series with a circuit element to measure the current that was flowing through it. An ideal ammeter would have zero resistance, so it wouldn’t change the current that was originally flowing.
A voltmeter is wired in parallel with a circuit element in order to measure the voltage difference across it. An ideal voltmeter would have infinite resistance, so it wouldn’t shunt any current around the element, and thus, would not change the original voltage difference that was present.