TL;DR: I would vote to close this as a duplicate of Gantt chart package based on the OP's comment.
Here are my comments based on your choices:
Ask @ClaudioFiandrino to give an answer. But there is nothing to explain! Why bother?
Based on what I can see, @ClaudioFiandrino is not affiliated with that post in any way. So, no.
Answer it with a MWE and some explanation. But the OP did not ask for it; they are satisfied with the comment.
This doesn't really matter. If you want to add an answer then so be it. The mentioned comment by @JLDiaz is very generic and doesn't really suggest "ownership" over some form of answer... Technically comments aren't answers; we extend a courtesy towards the author of a possible answer-in-comment.
Close as too broad. This is how we treat "do it for me"-questions. But again, OP is satisfied with the comment.
Yes, this is too broad, just by looking at the volume inside the answers to Gantt chart package. Specifically there are small things that could be fine-tuned in terms of a Gantt chart, and without those specifics people will end up answering the question in its current and possibly be bombarded with additional fine-tuning requests...
Close as primarily opinion-based, since theoretically one can accomplish it in many ways. But using
pgfgantt seems to be the "consensus", not an opinion.
I would say no here, just because it's very broad. Perhaps there might be some overlap, but I don't think the question is posed in such a way that "it solicits primarily opinion-based answers".
Close as duplicate, to "Gantt chart package". This is subtle. Can we mark questions as duplicate just because they have the same answer?
Most certainly! The Guidelines for reviewing Close Votes mentions:
Remember we are asking whether an answer is found at the duplicate-linked question moreso than whether the questions are identical. You should look at the question linked and verify that it has an answer to the question being proposed for closure. If it doesn't, it should not be closed as a duplicate. (You can't vote to close questions as duplicates when the proposed target has no upvoted or accepted answer(s).)
I use this approach regularly, since people approach problems from different angles, thereby leading to different questions. However, they're essentially after the same thing, which provides the common answer. Moreover, if others don't share your sentiment they can opt to vote differently; the SE network setup allows for that. ;)