If the circuit is on, put DMM to volts, and if there is a reading, the fuse should be replaced. If the circuit is off, take the fuse out, put DMM on resistance, if there is zero ohms, the fuse should be replaced. Since they ask "using a voltmeter", I don't think they would want an answer that had to do with measuring resistance. Saying how to test a fuse using resistance is better than nothing.

I would use a multi meter that has the ability to reach 1 Ohms range. Next I would set the meter to read resistance and then connect the leads to each end of the fuse so that the meter can test the series circuit tell you if the fuse has continuity, end to end.