"이것은 무슨 빵입니까?"
"What kind of bread is this?"
I would say the original Korean sentence doesn't really sound unnatural to me; I think one definitely may repeat 빵 when both the subject and the complement are emphasised. I am adding alternative answers without repetition of the same word, but I am not entirely sure as to whether such repetition is more common in Korean than it is in English.
I think some people are missing the point of the exercises. These sentences appear to combine past and present learning topics, and sometimes a complex sentence for beginners can sound really bizarre or unnecessarily complicated. If we were learning phrases, then I would question the examples (like the one above). However, the intent is to learn a skill and apply that knowledge to everyday conversations. With more practice, we can begin to form (hopefully, not as strange ;b) sentences of our own. 화이팅!
I answered "this bread, what kind is it?" And got it wrong, but i think (in english) it is grammatically correct and is a rephrasing of "what kind of bread is this?" so should that not be correct? Forgive me, I'm still having trouble with some of these concepts. Thank you to anyone who answers!