Refer to figure.
062.02.04.01.06: State that the pairing of VHF and UHF frequencies (VOR/DME) enables the selection of two items of navigation information from one frequency setting.

Frequency pairing allows the tuning of one frequency but the receipt of additional signals as well, possibly from other frequency bands. Think of the ILS - you only tune the VHF localiser frequency but you also receive the UHF glideslope.

VOR/DME is the same - you only tune the VHF VOR frequency but you also receive the UHF DME that has been frequency paired - without having to tune both frequencies individually.

It is important that you remember which radio aid operates in which frequency band; in this case the VOR is VHF and the DME is UHF. If you remember that, the answer is fairly straight forward as the VOR and DME are in different frequency bands so they must be frequency paired. They cannot possibly be the same frequency.