Choose the correct words to insert in each of the following sentences. Then select the letter of the correct response. ____ on the sales staff must have ____ presentation ready by Friday.

A) Everyone, their
B) Everyone, his or her
C) Everyone, your

Using "their" in this context is grammatically incorrect, as it is a plural pronoun that does not agree with the singular noun "everyone." "Your" is also incorrect, as it suggests that the presentation will belong to the sales staff individually, rather than collectively. Therefore, "his or her" is the correct choice that agrees with the singular "everyone" and avoids gender bias.