What is the purpose of the cause-and-effect signal word “therefore”?

There are no options for me to pick

Singular third person pronouns are “he,” “she,” “it,” “his,” “hers,” “him” and “her,” and third person plural pronouns are “they,” “them” and “their.” the number of people to which you are referring should always match the pronoun you choose (“he” to refer to one male, “they” to refer to more than one male).