His father is a doctor who treats children and infants.

A. Dermatologist

B. Gynaecologist

C. Podiatrist

D. Paediatrician

Answer: Option D

Solution(By Examveda Team)

One word substitute is Paediatrician.

Dermatologist: a medical practitioner qualified to diagnose and treat skin disorders.
Gynaecologist: a physician or surgeon qualified to practise in gynaecology.
Podiatrist: a person who treats the feet and their ailments; a chiropodist.
Paediatrician: a medical practitioner specializing in children and their diseases.