A doctor who treats skin diseases:

Ophthalmologist
Dermatologist
Paediatrician
Cardiologist

The correct answer is: B. Dermatologist.

A dermatologist is a doctor who specializes in the diagnosis and treatment of skin diseases. They can also provide cosmetic treatments, such as laser hair removal and wrinkle reduction.

An ophthalmologist is a doctor who specializes in the diagnosis and treatment of eye diseases. They can also provide vision correction surgery, such as LASIK.

A pediatrician is a doctor who specializes in the diagnosis and treatment of children’s diseases. They can also provide well-child care and vaccinations.

A cardiologist is a doctor who specializes in the diagnosis and treatment of heart diseases. They can also provide cardiac surgery, such as bypass surgery.