Which expression should you use?

You create a SQL Server 2008 Reporting Services (SSRS) report for a school district.
The school district needs to be able to retrieve the median value of all test scores.
You build a custom function named Median that accepts the test scores and returns the
median test score.
You need to run this custom function.
Which expression should you use?

A.
=Execute Function Median(Fields!TestScores)

B.
=Code.Function.Median()