I'm wondering what the best way is to deal with a new question which has already been answered on a previous highly upvoted question, but where the old answer is no longer valid.

The question Whats is the best user to manage webserver? recently showed up in the review queue. At the time, I voted to close it as a duplicate of What's the best way of handling permissions for Apache 2's user www-data in /var/www?.

However, as Esa Jokinen pointed out, the accepted answer to the older question may have been best practice at the time, but they aren't now, and anyone following those instructions will risk security issues and other problems.

As I see it, there are three possible ways to handle this:

1. Let the new question remain open, and upvote Esa's excellent answer. This has the advantage of a better answer being available, but the downside that searchers are likely to find the old question first since it has a high number of upvotes.
2. Close the new question as a duplicate, and move Esa's answer to the old question. This has the upside that searchers will find the question that has the new and improved answer, but the downside that Esa's answer won't be the accepted one.
3. Close the old question as a duplicate of the new one. This has the upside that the open question will be the one with the current answer, but the downside that people might still read only the last one.

Which would be the best way to handle this particular question, to make sure that the people reading this site can find the best response?

I'm wondering what the best way is to deal with a new question which has already been answered on a previous highly upvoted question, but where the old answer is no longer valid.

The question Whats is the best user to manage webserver? recently showed up in the review queue. At the time, I voted to close it as a duplicate of What's the best way of handling permissions for Apache 2's user www-data in /var/www?.

However, as Esa Jokinen pointed out, the accepted answer to the older question may have been best practice at the time, but they aren't now, and anyone following those instructions will risk security issues and other problems.

As I see it, there are three possible ways to handle this:

1. Let the new question remain open, and upvote Esa's excellent answer. This has the advantage of a better answer being available, but the downside that searchers are likely to find the old question first since it has a high number of upvotes.
2. Close the new question as a duplicate, and move Esa's answer to the old question. This has the upside that searchers will find the question that has the new and improved answer, but the downside that Esa's answer won't be the accepted one.
3. Close the old question as a duplicate of the new one. This has the upside that the open question will be the one with the current answer, but the downside that people might still read only the last one.

Which would be the best way to handle this particular question, to make sure that the people reading this site can find the best response?