Which value should you select for the AggregationFunction property for the Average Rate measure?

You are developing a SQL Server Analysis Services (SSAS) cube for the accounts
department.
You create a measure group named Exchange Rate that consists of measures pertaining to
currency exchange rates. One of the measures in this group is named Average Rate and it
will be used to report the average currency exchange rate over time.
Currently the AggregationFunction property for the Average Rate measure is set to Sum.
You need to ensure that Average Rate measure reports the average of the currency
exchange rate over time.
Which value should you select for the AggregationFunction property for the Average Rate
measure? To answer, select the appropriate setting in the answer area.

Answer: See the explanation.

Explanation:
AverageOfChildren
Specifies average of leaf descendants in time. Average does not count an empty value as 0.