Q: What feature is required to collect the number of comments users posted to a web page?
A) Custom Channel Groupings
B) Calculated Metric
C) Custom Channel Groupings
D) Custom Metric
Correct Answer is D) Custom Metric.
Explanation:
custom metrics can produce more flexible and more readable custom reports and as such are a convenient way to track your most important metrics.
Read more here: https://support.google.com/analytics/answer/2709828?hl=en#example-metrics