Figure 4-38(c) shows a third alternative data model for the sheet-music-tracking problem. In this data model, use either Work_Version2 or Work_Version3, whichever you think is better.
a. Select identifiers for each entity in your data model. Justify your selection.
b. Summarize the differences between this data model and that in Figure 4-38(b). Which data model is better? Why?
c. Design a database for this data model. Specify key and foreign key columns.