Correct Answer: Dermatologist

Solution : The first option is the correct choice.

A dermatologist is a medical practitioner qualified to diagnose and treat skin disorders.

The meanings of the other options are:

• Ophthalmologist : a specialist in the branch of medicine concerned with the study and treatment of disorders and diseases of the eye.
• Cardiologist : a doctor who specialises in the study or treatment of heart diseases and heart abnormalities.
• Orthodonist : a dentist who is qualified to treat irregularities in the teeth and jaws.

Hence, the correct answer is dermatologist .