Explanation:

- Option 1: Ophthalmology

- This is the field of medicine that deals with the diagnosis and treatment of eye disorders.

- It involves medical and surgical care for eye diseases.

- Option 2: Oncology

- This is the study and treatment of cancer.

- Oncologists manage a patient’s care throughout the course of the disease.

- Option 3: Obstetrics

- This field deals with pregnancy, childbirth, and the postpartum period.

- Obstetricians specialize in the health of the mother and baby during this time.

- Option 4: Orthopedics

- This is the branch of medicine concerned with conditions involving the musculoskeletal system.

- It includes the treatment of bones, joints, and muscles.