- Where users came from before reaching your site
- The device types, desktops and mobile phones
- The date range setting for the last 30 days
- How many users were on mobile phones
The correct answer is: How many users were on mobile phones
Metrics are quantitative measurements. The metric Sessions is the total number of sessions. The metric Pages/Session is the average number of pages viewed per session.
user metrics are calculated in two basic ways:
As overview totals
where the metric is displayed as a summary statistic for your entire site, such as bounce rate or total pageviews.
In association with one or more reporting dimensions
where the metric value is qualified by selected dimension(s).
Read more here: https://support.google.com/analytics/answer/1033861