The correct answer is: B. To describe the data that should be entered in each field.
The description column in Table Design View is used to provide a description of the data that should be entered in each field. This information can be helpful for users who are trying to understand what data should be entered in each field. It can also be helpful for developers who are trying to understand the structure of the table.
Option A is incorrect because the data type is defined in the Data Type column.
Option C is incorrect because lookup data is entered in the Lookup tab of the Field Properties dialog box.
Option D is incorrect because the description column is used to provide a description of the data that should be entered in each field.