Option B
Orthopaedist: An orthopaedic surgeon, a doctor who corrects congenital or functional abnormalities of the bones with surgery, casting, and bracing.
Gynaecologist a physician or surgeon qualified to practice in functions and diseases specific to women and girls, especially those affecting the reproductive system.
Nephrologist is a medical doctor who specializes in kidney care and treating diseases of the kidneys.
Dermatologist is a medical practitioner qualified to diagnose and treat skin disorders.
Kidney and skin are parts of a body. Females is the only option which represents group of people like children which is the correct option.