Final answer:
A natural join links tables by selecting rows with common values in their common attributes, merging rows with matching values from both tables.
Step-by-step explanation:
A natural join links tables by selecting only the rows with common values in their common attribute(s). The correct option is d. natural. A natural join is a type of database join that combines tables based on column(s) with the same name and datatype. This type of join assumes that the fields with the same names in both tables have a logical relationship and automatically uses these common attributes as the join criteria, merging the rows with matching values.