Is it OK to answer a question, where someone had commented on the question with information that can really be used as an answer?
I thought of this when I came across this link where Menachem commented on the question but didn't actually submit it as an answer to the question. My consideration for answering the question was that his comment was over 4 years old, and it still didn't move to an answer.
Of course, I credited Menachem in my answer, but I was wondering if it's appropriate to do when coming across an old question which no one answered yet, and the comments hint (or even explicitly state) an answer.