The correct answer is: A. Tharu
The Tharu are an ethnic group native to the Terai region of Nepal and India. They are considered to be one of the oldest inhabitants of the region. The Tharu are a Mongoloid people, and they share many physical features with other Mongoloid groups, such as the Chinese, Japanese, and Koreans. These features include a relatively small stature, a broad face, and epicanthic folds (folds of skin that cover the inner corner of the eye).
The Tharu are a diverse group, and there are many different sub-groups within the Tharu community. However, they all share a common culture and history. The Tharu are traditionally farmers, and they live in small villages. They are a matrilineal society, which means that property and inheritance are passed down through the female line.
The Tharu are a religious people, and they worship a variety of gods and goddesses. They also have a strong belief in spirits and ghosts. The Tharu are a fascinating group of people, and they have a rich culture and history.
The other options are incorrect because they are not Mongoloid peoples. The Oraon are an Austroasiatic people, the Gond are an Indo-Aryan people, and the Santhal are an Austroasiatic people.