"저것이 무엇이냐고 했습니다."
Translation:I asked what that is.
I think so. This website explanation really helps: https://www.howtostudykorean.com/unit-3-intermediate-korean-grammar/unit-3-lessons-51-58/lesson-53/
Imo the distinction would be if you are stating a fact about what you asked you would say 'that is' vs if you wanted to emphasize that you were asking a question you would ask 'is that'.<pre>
I agreed with you until i changed the emphasis to 'is' in my head. Then it made sense.</pre>