I was afraid of ambiguation, but the thing is that city in Russia is called Petropavlovsk-Kamchatskiy. I don't know how many of Russians call it just Petropavlovsk, but most of us know both Petropavlovsk (in Kazakhstan) and Petropavlovsk-Kamchatskiy. This quiz was created on Russian segment, I thought for Russian-speakers it would be quite clear which Petropavlovsk I mean.
If it was an English quiz, then I think I never would add Petropavlovsk, or at least I'd also add Petropavlovsk-Kamchatsky.
If it was an English quiz, then I think I never would add Petropavlovsk, or at least I'd also add Petropavlovsk-Kamchatsky.