The correct answer is option 4. "NOT". Boolean operators are commands used in search engines to define the relations among the words that the search must or must not include. The Boolean operator "NOT" is used to exclude a term in a research. For example if you want to look for all universities but Harvard, you can search "universities NOT Harvard"
When using any search engine, there are actually functions (terms) known as Boolean operators that one can type into the search bar that assist in the research one is doing. You know how when searching the internet, you might have to sift through many “hits” that you find useful because information that is not useful keeps being included? What you can do, thus, is include the command “NOT” (in all capital letters) after your main search terms followed by words you no longer want to see, and the search engine should provide results without the terms following NOT. For instance, you if did an internet search for “pets” but did not want your results to include dogs, if you typed in the following, your results would be largely without the word “dogs”:
