Duration of meetings in sprints

Both.

That is a trick question.  There are no meetings described in the Scrum framework.  

But since people often mistake the Scrum Events for meetings I agree with @Ian Mitchell.  Both of those conditions are true. 

BTW, it appears that you are doing some kind of assessment or testing.  Mind sharing where you are getting these questions? 

I'd echo both Ian and Daniel.

If these are coming from some kind of assessment, I'd have serious questions about the quality of that assessment. It doesn't seem to be well-aligned with the values and principles of agility or the Scrum framework. It may be better to find new resources to work with.

That said:

Scrum doesn't call them meetings, but events. In my experience, a "meeting" often evokes thoughts of talking. The Scrum events - Sprint Planning, Daily Scrum, Sprint Review, and Sprint Retrospective (and the Sprint itself) - are about getting things done. They are more of a working session to achieve a specific outcome rather than people talking about something. Plus, it's always good to use the correct terminology to make sure everyone can easily understand each other.

The events have a maximum timebox: 8 hours for Sprint Planning, 15 minutes for the Daily Scrum, 4 hours for Sprint Review, and 3 hours for Sprint Retrospective. These timeboxes are based on what a Scrum Team should require to achieve each event's desired outcomes for a 1 month Sprint. The only event's timebox that isn't based on a Scrum Team working in a 1 month Sprint is the Daily Scrum. For the other events, the team may scale down their timebox for Sprints that are less than 1 month, but this isn't required.

I'd also point out that these are maximum timeboxes. If you have a 2 week Sprint, you can choose to timebox Sprint Planning at 8 hours, or perhaps scale it down to 4, or learn that your team can usually complete it in 3. The event can end whenever its objectives and outcomes have been satisfied, though. Even if you held 8 hours for Sprint Planning, you don't need to have the team sit around for 8 hours. Once the outcomes have been met, the team can get to work on executing their plan. The same goes for all of the events.