Question

review the map of global migration patterns. what is the purpose of the key on this map? it lists the number of people who migrated from each location. it shows the type of transportation used to travel from place to place. it explains the periods represented by the different arrow colors. it provides the reasons why people migrated from one region to another. migration dates: 200,000 years ago, 70,000–50,000 years ago, 45,000–35,000 years ago, 3,500 years ago

Explanation:

The key (legend) has "Migration Dates" with colors linked to time periods (e.g., 200,000 years ago, 70,000 - 50,000 years ago). So it explains periods via arrow colors. Other options: A (no number listing), B (no transport type), D (no reasons).

Answer:

It explains the periods represented by the different arrow colors.