shouldn't it accept 밥을 요리해요? Since 저는 is optional depending on context
Is there any difference in usage between 쌀 and 밥?
The first refers to the uncooked version, while the second refers to the cooked version and any other meal.
Why we use 나는 here?
Depending on the situation it could have been 제가, 저는, 나는. Sometimes DL will not have considered every correct answer, so it is helpful to file a report when your right answer is not accepted.
using 나 with the humble verb ending is inappropriate
using 나 is not appropriate when the humble ending is used
So I wrote '밥을 짓습니다' cuz I thought '저는' was omitted, but regardless of that it just gives me a wrong answer that '짓습니다' doesn't make sense. HOW
밥을 요리해요 should also be accepted since not always it's used the pronoun