6. Explain why
urbanization
occurs?

Urbanization occurs in developing countries that are adapting to the new world and it's ways. The world's cities are growing because people are moving from rural areas in search of jobs, opportunities to improve their lives and create a better future for their children.

Hope that helps if it did please give me brainiest! Thanks and have a great day! <333

d. i assume the underlined word is "role." reformat if it isn't.

explanation:

role is closest to part because when replacing words, "playing a vital decision," "playing a vital activity," and "playing a vital dollar" don't make logical sense. the only meaningful choice is "playing a vital part."

this fits one of merriam-webster's definitions of role: "a function or part performed especially in a particular operation or process."