Which of the Following Is True of a Measure in Power

Which of the following is true of a measure in Power Pivot technology?

A) A measure is the same thing as a calculated column.
B) A measure is a summarization of any single column in a Data Model table.
C) A measure is a summarization of data in one or more tables of a Data Model,created with a DAX formula,to be used in the Values area of a pivot table.
D) A measure is a formula for summarizing data,to be used in the Values area of a pivot table,and it can be based on the usual built-in Excel functions; no DAX functions are necessary.