In this case, "each group member" is the appropriate choice to maintain a consistent singular reference, as "the students" refers to all members of the class. "Each group member" indicates the singular responsibility of outlining their roles, following the conventions of Standard English.

Here, the correct choice of pronoun-antecedent agreement is "either of them" because it is unknown whether Mark or Tim is responsible for catering, both being singular references. Using "either of them" provides a consistent singular reference and follows the conventions of Standard English.

The correct choice for pronoun-antecedent agreement is "everyone," as it refers to both the teacher and the students who are involved in the situation. Using "everyone" maintains consistent singular reference and aligns with the conventions of Standard English.

The correct choice of pronoun-antecedent agreement is "hers" because the context implies that the book either belongs to Sarah or Natalie, and both are female. Using "hers" maintains a consistent singular reference and aligns with the conventions of Standard English.

In this case, "each member" is the appropriate choice to maintain a consistent singular reference, as "team members" refers to all individuals. "Each member" indicates the singular responsibility of each member, which follows the conventions of Standard English.