Which MDX function should you use in line 03?

HOTSPOT
You are developing a SQL Server Analysis Services (SSAS) cube.
You are writing the following Multidimensional Expressions (MDX) statement for use by a
calculated measure. The measure computes the sales amount for the same time period of
the previous year. (Line numbers are included for reference only.)

You need to complete the MDX statement.
Which MDX function should you use in line 03? To answer, select the appropriate MDX
function in the functions list.

Answer: