5 points) Consider the following statements about Social Accounting Matrices (SAM): 1 . A SAM provides a systematic representation of the circular flow of income and expenditure within an economy. 2. In a SAM, the "knots of transactions" capture the detailed entries that represent the flow of goods and services between different sectors and agents in an economy .3. The structure of a SAM is typically presented in a linear list format 4. A balanced SAM ensures that the total value of imports is equal to the total value of exports 5. SAMs are primarily used for input-output analysis to understand the linkages between sectors of an economy. Which of the above statements are TRUE are true is it 1,3,4 only or not