Only easy if you already knew it was a "het" word. If you'd assumed it was a "de" word, impossible to work out from the question whether it's prompting for singular or plural. :(
Well but that means plural can't be wrong. Or different there is no need to know if 'moment' is a het word or not.
It's less easy for Germans, though. Usually, German and Dutch genders overlap neatly. Der/die is de, and das is het. For a short period of or point in time we say "der Moment" in German, although the physical moment (when something is in motion) is "das Moment". The gender is a kind of false friend here, since I'd expect it to be "de moment" in Dutch.
Why wouldn't "De moment" also be correct since we could be saying "The moments" or "The moment"? We aren't translating anything here.
Another good question is ... how would you translate the english "The moment" (singular) into Dutch?