The correct answer is either an asterisk “*” or a question mark “?.”
Wildcards are an advanced search technique that maximizes your search results. An asterisk is normally used at the end of a root word in order to find results of for various ending of a root word. One example would be educa*, which would search for any term that starts with educa. A question mark is used to represent a single character anywhere in a word. An example search term would be “colo?r.” This would generate results for both color or colour.