A labor and delivery nurse is caring for a 26-year-old G1P0 client who was admitted in active labor. The provider has ordered vaginal exams as indicated. In which of the following situations would the nurse appropriately perform a vaginal exam?

Before administering analgesic or anesthetic medications.

When the membranes rupture or an abnormal fetal heart rate pattern is observed.

On admission to determine baseline cervical dilation and effacement.

Every hour to check for progression of labor.

The client is positive for Group B Streptococcus.