Final answer:
In the list of words presented, the adverb is 'carefully,' which modifies the verb 'checked' by indicating the manner in which the action is performed.
Step-by-step explanation:
The word carefully is the adverb in the given list of words. An adverb is a word that modifies a verb, an adjective, or another adverb, often describing how, when, where, or to what extent something is done.
In the example, "Alex carefully checked answers," the adverb 'carefully' modifies the verb 'checked' by explaining how Alex performed the action of checking.