If users must enter text in a LastName field,you can set the _____ property for the field in Table Datasheet view.

A) Unique
B) Indexed
C) Default Value
D) Required

The best choice is to set the Required property for the LastName field. This will ensure that all records entered into the table have some value in the LastName field. If the field is left blank, Access will prompt the user to enter a value before the record can be saved. Setting the Unique or Indexed property may help with data validation and searching, but it does not enforce the requirement for a value in the field. The Default Value property would not be appropriate in this case since each record should have a unique and specific value entered by the user.