Final answer:
The correct statement to teach the adolescent how to manage pain through PCA via an epidural is Option 3: "You can request additional doses from the nurse if you think it's necessary."
Step-by-step explanation:
Option 3: "You can request additional doses from the nurse if you think it's necessary." is the correct statement when teaching this adolescent how to manage pain through patient-controlled analgesia (PCA) via an epidural. PCA allows the patient to self-administer pain medication within prescribed limits. By choosing Option 3, the patient can communicate their pain level and request additional doses if needed, ensuring they receive adequate pain relief.