From naver dictionary:
시험지 따위에서, 답을 적는 난.
다음 문제를 읽고 보기에서 맞는 답을 골라 답란에 적으시오.
If we search for the meaning of 欄, this is specified as both 란 and 난 in Korean.
Meaning of 난 is
(신문등의) a column; a page; a section; (기입하는) a blank
So I suppose it means the blank space where you're supposed to fill in your answer,...
It's not accurate to say the word "flower" is repeated: first of all, "flower" is an English word, and "무궁화 꽃" only contains "-화" and "꽃", both being Korean. :)
More seriously, just because the word "무궁화" is translated to "Hibiscus flower" doesn't mean the word contains "flower" ...
꽃 is both a regular noun for "flower" and a suffix-like word that attaches to names of flowers to make the meaning clearer. Since 무궁화 is a name of the flower, you can say either 무궁화가 피었습니다 or 무궁화꽃이 피었습니다, but the latter is probably more common. Think of it as habit.
Saying 무궁화꽃 instead of 무궁화 is especially popular among kids. The phrase 무궁화 꽃이 ...
The base form -게 되다 signifies coming to a certain state or ending up doing something, without saying the exact reason or course of events that led to it.
가게 됐어요 means the decision has been made for the person to go (either by themselves or by others). So it means they did not go yet, but they will in due time. -ㅆ어요 here describes a completed state, where ...