Final answer:
The Native Americans arrived in the Americas through the Bering Land Bridge around 15,000 years ago. They crossed the land bridge in search of food and later settlers came by boat across the Bering Strait. So, the correct answer is option b. By land via a land bridge from Asia around 15,000 years ago.
Step-by-step explanation:
The Native Americans arrived in the Americas through the Bering Land Bridge around 15,000 years ago, not by sea. During the last ice age, a land bridge called Beringia existed between Asia and North America.
The first inhabitants, migrating in search of food, crossed this land bridge. When the glaciers melted, water engulfed Beringia, forming the Bering Strait. Later settlers came by boat across this narrow strait.
According to the options provided, the correct answer is b. By land via a land bridge from Asia around 15,000 years ago.