"They touch the elephant."
Translation:Eles tocam no elefante.
In Portugal I think we would never say "tocar o elefante", it seems like the elephant is a musical instrument. But in Brazil I think they do.
As for when to use the word "no" with the verb "tocar"... If this helps, remember: Eles tocam piano = they play (the) piano Eles tocam no [no=em+o] piano = they touch the piano
It would kind of work like "I am speaking Russian" Vs "I am writing ON THE russian" (the first one implies you're using something - the Russian language - while the second one implies you're doing something on the object - a Russian person).
And very rarely we say "ele toca o piano", meaning "he plays (the) piano" but never meaning "he touches the piano".
I'd argue that adding elas/eles assumes context that isn't given by the word "they" in English. To capture the ambiguity, I'd avoid trying to translate "they" into the suggested options (though I suppose vocês is as ambiguous as the English "they," but it also assumes a formality to the interaction).