Native polish here. Given sentence would rather translate to: "Robię zupę cebulową i marchwiową".
"Robię zupę z cebulą i marchewką" should be: "I am making a soup with onion and carrot".
with = z, and "with" is missing in the English sentence.
I don't understand why both 2 and 3 are correct? Two different forms of carrot?
Unfortunatelly, we don't know what "2" and "3" mean.
Choice 2 uses 'marchewka' and choice 3 uses 'marchwia' and apparently both are correct forms for carrot. I am sorry I don't have the ability of writing 'a' with a little tail.
".marchewka" and marchew" are two forms of the same word and both are in common use
Thank you for your reply.
It's called ogonek (which does indeed mean tail).
very interesting ! Thank you for your input. I learn something new every day.