Answer: Meg is right.
Step-by-step explanation:
The correct way to measure a current with an ammeter, is placing the instrument in series with the circuit to mesure.
This means that the circuit must be opened to insert the ammeter, that must have an internal resistance as low as possible so it doesn't disturb the circuit.
If one of the wires leading to the ammeter has a bad contact, as the circuit is in series with the instrument, it can open the enrire circuit, so no current can flow through it anymore.
The voltmeter, instead, is connected in parallel to the circuit to be measured, trying to measure the voltage between two points without disturbing it.
If one of the wires disconnects from the circuit, as ideally no current must flow through the instrument, the impact on the circuit would be negligible, although obviously it would fail to measure the desired voltage.