The correct answer is: C. Field name
A field name is a unique identifier for each column in a table. It is used to reference the data in the column. The field name is displayed at the top of each column in Datasheet View.
A data type is a set of rules that defines the kind of data that can be stored in a column. The data type of a column determines what kind of values can be entered into the column and how the data is stored and processed.
A description is a brief explanation of the purpose of a column. The description is displayed in the Status bar when the cursor is in the column.
A primary key is a column or set of columns that uniquely identifies each row in a table. The primary key is used to enforce referential integrity between tables.