A protection mechanism to limit inferencing of information in statistical
database queries is:

A.
Specifying a maximum query set size

B.
Specifying a minimum query set size, but prohibiting the querying
of all but one of the records in the database

C.
Specifying a minimum query set size

D.
Specifying a maximum query set size, but prohibiting the querying
of all but one of the records in the database

Explanation:
When querying a database for statistical information, individually
identifiable information should be protected. Thus, requiring a
minimum size for the query set (greater than one) offers protection
against gathering information on one individual. However, an attack
may consist of gathering statistics on a query set size M, equal to or
greater than the minimum query set size, and then requesting the
same statistics on a query set size of M + 1. The second query set
would be designed to include the individual whose information is
being sought surreptitiously.
*Thus with answer “Specifying a minimum query set size, but prohibiting the querying
of all but one of the records in the database”, this type of attack
could not take place.
* Answer “Specifying a minimum query set size” is, therefore, incorrect since it leaves
open the loophole of the M+1 set size query. Answers “Specifying a maximum query set size” and
“Specifying a maximum query set size, but prohibiting the querying
of all but one of the records in the database” are incorrect since the critical metric is the minimum
query set size and not the maximum size. Obviously, the maximum query set size
cannot be set to a value less than the minimum set size.