**Explanation:**
The natives of North America belong to the Mongoloid racial group. Here is an explanation of the various racial groups and why North American natives fall into the Mongoloid category.

**Austric:**
The Austric racial group refers to the indigenous people of Southeast Asia and Oceania, including the Austronesian-speaking populations. This racial group does not include the natives of North America.

**Caucasoid:**
The Caucasoid racial group includes people from Europe, North Africa, the Middle East, and the Indian subcontinent. This racial group does not encompass the natives of North America.

**Mongoloid:**
The Mongoloid racial group includes populations from East Asia, Central Asia, Southeast Asia, and the Arctic regions. The natives of North America, commonly referred to as Native Americans or First Nations, fall into this racial group.

- Native Americans are believed to have migrated from Asia to North America via the Bering Strait during the last Ice Age.
- They share physical characteristics such as straight black hair, dark eyes, and a yellowish-brown skin tone with other Mongoloid populations.
- Mongoloid populations are also characterized by a low nasal bridge, epicanthal folds, and shovel-shaped incisors, which are commonly found among Native Americans.
- The genetic and anthropological evidence supports the Mongoloid classification for the natives of North America.

**Negroid:**
The Negroid racial group refers to populations from sub-Saharan Africa and some parts of the Indian Ocean region. The natives of North America do not belong to this racial group.

In conclusion, the natives of North America belong to the Mongoloid racial group, which includes populations from East Asia, Central Asia, Southeast Asia, and the Arctic regions. They share physical characteristics and genetic traits with other Mongoloid populations, supporting their classification within this racial group.