I know that Americans call "jam" "jelly", but in Australia (and I believe in the UK), jelly is a very different thing.
Would it be correct to say that the Italian "marmellata" is the same as the america "jello"? If not, then it's not correct as the Australian "Jelly".
I would love to see duolingo provide an British English native language alongside US English.
It's not true that we call all fruit and sugar preserves jam - we call preserves made from just the strained juice jelly too, it's just that we are more likely to eat jam so don't use it in that sense so often. But you see bramble jelly and apple jelly in the shops.
I agree we would never use the American brand name, we use the traditional name jelly for a set wobbly dessert.
This doesn't actually matter but in the US we use BOTH jam and jelly (and preserves) to refer to slightly different products. The two words are sometimes used interchangeably, though. The most common product we use is jelly so that's why it's in greater usage. Jelly has no fruit chunks in it and has more sugar (and is usually a bit cheaper) than jam.
In summary, Australians call this jelly: http://retireyoung.com.au/wp-content/uploads/2010/11/red-jelly.jpg And this jam: http://www.doriegreenspan.com/images/blueberry%20peach%20jam.jpg
And that's why this question should be revised (marmaletta shouldn't mean jelly in British English)