Final answer:
The answer is A) 5. Approximately 1 out of every 5 people alive had migrated out of their country of birth.
Step-by-step explanation:
The answer to the question is A) 5.
According to the information provided, a 2007 estimate found that roughly 1 out of every 5 people alive had migrated out of their country of birth. This means that out of every 5 people, one person had migrated.
This information highlights the significant impact of migration on a global scale.