Which of the following statements correctly synthesizes two migration scales?

a. A population census is only useful in identifying local migration trends.
b. Internal migration at the local level occurs less frequently than national external migration.
c. Trends of globalization can create global migration patterns such as migration corridors.
d. National economic push factors in developing countries can create global migration patterns.

c. Trends of globalization can create global migration patterns such as migration corridors.

c. Trends of globalization can create global migration patterns such as migration corridors.

To find the correct statement that synthesizes two migration scales, let's examine each option:

a. A population census is only useful in identifying local migration trends.
This statement only mentions local migration trends, so it does not address multiple scales of migration.

b. Internal migration at the local level occurs less frequently than national external migration.
This statement compares internal migration at the local level with national external migration. While it acknowledges two scales of migration, it presents a comparison rather than a synthesis.

c. Trends of globalization can create global migration patterns such as migration corridors.
This statement acknowledges the influence of globalization on global migration patterns, thereby synthesizing the global scale with the concept of migration corridors.

d. National economic push factors in developing countries can create global migration patterns.
This statement brings together national economic push factors in developing countries and global migration patterns, suggesting a connection between them. It synthesizes the national and global scales of migration.

Based on our analysis, the answer is option d: "National economic push factors in developing countries can create global migration patterns."