You are developing a SQL Server 2008 Analysis Services (SSAS) solution which includes a
time dimension called TestTime which includes a hierarchy called Year-By-Day for
Company.com. You own a measure called Number from a measure group called
MeasureTester. In the previous time period for the current level of the Yer-Bet-Day
hierarchy, you should make sure that you develop a calculated member to show the Number
measure. Which is the correct answer?

A.
You should utilize [Measures].[ Number],OPENINGPERIOD [TestTime].[Yer-BetDay].FirstSibling.Level))

B.
You should utilize ([Measures].[ Number],LASTPERIODS( 0,[TestTime].[Yer-BetDay].PrevMember))

C.
You should utilize ([Measures].[ Number],LASTPERIODS( 1,[TestTime].[Yer-BetDay].PrevMember))

D.
You should utilize ([Measures].[ Number],[ TestTime].[Yer-Bet-Day].NextSibling)

Explanation:
LastPeriods (MDX)
SQL Server 2008 R2 Other Versions Returns a set of members up to and including a
specified member.
Syntax LastPeriods(Index [ ,Member_Expression ] )
Arguments Index – A valid numeric expression that specifies a number of periods.
Member_Expression – A valid Multidimensional Expressions (MDX) expression that returns a
member.
Remarks
If the specified number of periods is positive, the LastPeriods function returns a set of
members that start with the member that lags Index – 1 from the specified member
expression, and ends with the specified member.
The number of members returned by the function is equal to Index.
If the specified number of periods is negative, the LastPeriods function returns a set of
members that start with the specified member and ends with the member that leads (- Index
– 1) from the
specified member. The number of members returned by the function is equal to the absolute
value of Index.
If the specified number of periods is zero, the LastPeriods function returns the empty set.
This is unlike the Lag function, which returns the specified member if 0 is specified.

If a member is not specified, the LastPeriods function uses Time.CurrentMember. If no
dimension is marked as a Time dimension, the function will parse and execute without an
error, but will cause a cell error in the client application.
Examples
The following example returns the default measure value for the second third, and fourth
fiscal quarters of fiscal year 2002.
SELECT LastPeriods(3,[Date].[Fiscal].[Fiscal Quarter].[Q4 FY 2002]) ON 0 FROM
[Adventure
Works]
Note
This example can also be written using the : (colon) operator:
[Date].[Fiscal].[Fiscal Quarter].[Q4 FY 2002]: [Date].[Fiscal].[Fiscal Quarter].[Q2 FY 2002]
The following example returns the default measure value for the first fiscal quarter of fiscal
year
2002. Although the specified number of periods is three, only one can be returned because
there are no earlier periods in the fiscal year.
SELECT LastPeriods (3,[Date].[Fiscal].[Fiscal Quarter].[Q1 FY 2002] ) ON 0 FROM
[Adventure
Works]