Answer:
B. eliminate unwanted topics to narrow down your search
Explanation:
NOT is part of Boolean operators, which includes AND, & OR. Boolean operators are used searching, which can either used for narrowing down searches, or broaden the searches by connector function.
Boolean is a baisic part of mathematical sets and database logic.
NOT operator is used in searching to achieve the following:
1. Eliminate words from searches
2. Narrow your searches, by eliminating the implied words from database.
for example: hard drugs NOT medicine.
